<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，方法重载是指在同一个类中定义多个方法，这些方法具有相同的名称，但参数列表不同。方法重载的主要优点是，它允许您使用相同的方法名称来执行不同的操作，这使代码更具可读性和灵活性。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">方法重载需要满足两个条件：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">方法名必须相同</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">参数列表必须不同</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">参数列表的不同可以包括参数的数量、类型或顺序。例如，以下两个方法就是重载方法：</p><pre class="brush:as3;toolbar:false">public int add(int x, int y) { return x + y; } public double add(double x, double y) { return x + y; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个例子中，我们定义了两个名为 add 的方法，一个用于整数，一个用于双精度浮点数。这两个方法具有相同的名称，但参数类型不同。Java编译器可以根据传递给方法的参数类型来确定应该调用哪个方法。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">方法重载的优点：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">可读性：方法重载可以使代码更易读。在许多情况下，一个名称描述的所有操作都是相关的。使用相同的名称对所有操作进行描述，可以使代码更清晰、更易于阅读和理解。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">灵活性：方法重载可以使代码更灵活。例如，在一个方法中，可以根据传递给它的参数类型和数量执行不同的操作。这使得方法更具可重用性和灵活性。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">避免名称冲突：使用相同的名称和不同的参数列表可以避免名称冲突。如果每个操作都有唯一的名称，那么在代码库中管理这些操作会变得更加复杂。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">需要注意的是，方法重载不能仅仅通过返回类型的不同来区分。Java编译器只会根据方法名称和参数列表来判断方法是否重载，而不会考虑返回类型。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，方法重载是一种非常常见的技术。通过使用相同的名称和不同的参数列表来定义多个方法，可以使代码更灵活、易读和易于维护。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
文章列表
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，有参数有返回值的方法是指在调用方法时需要传递参数，并且该方法在执行完成后返回一个值。该值可以是任何基本数据类型、对象类型或数组类型。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">定义有参数有返回值的方法的语法如下：</p><pre class="brush:as3;toolbar:false">public returnType methodName(parameterType parameterName) { // method body return returnValue; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">其中：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><ul class=" list-paddingleft-2" style="list-style-type: disc;"><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">public 表示该方法是公共的，可以被其他类访问。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnType 表示该方法的返回类型，可以是任何基本数据类型、对象类型或数组类型。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">methodName 表示该方法的名称。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">parameterType 表示该方法的参数类型，可以是任何基本数据类型、对象类型或数组类型。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">parameterName 表示该方法的参数名称。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">method body 表示该方法的具体实现。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnValue 表示该方法的返回值。</p></li></ul><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">例如，以下是一个有参数有返回值的方法的示例：</p><pre class="brush:as3;toolbar:false">public int add(int x, int y) { int sum = x + y; return sum; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，add 方法接收两个整数作为参数，将它们相加，并返回它们的和。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">可以通过以下方式调用这个方法：</p><pre class="brush:as3;toolbar:false">int result = add(2, 3); System.out.println(result); // 输出 5</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，我们将 2 和 3 作为参数传递给 add 方法，add 方法将它们相加并返回结果 5，然后将结果存储在 result 变量中。最后，使用 System.out.println() 方法输出结果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">需要注意的是，参数列表必须与方法定义中的参数类型和数量匹配，否则会导致编译时错误。此外，返回值必须与方法定义中的返回类型相匹配，否则也会导致编译时错误。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">有参数有返回值的方法在Java中非常常见。通过将数据作为参数传递给方法，以及从方法中返回数据，可以使代码更灵活、可重用，并使其更易于维护。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，有参数无返回值的方法是指在调用方法时需要传递参数，但该方法在执行完成后不返回任何值。这种方法通常用于执行一些操作而不需要返回结果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">定义有参数无返回值的方法的语法如下：</p><pre class="brush:as3;toolbar:false">public void methodName(parameterType parameterName) { // method body }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">其中：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><ul class=" list-paddingleft-2" style="list-style-type: disc;"><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">public 表示该方法是公共的，可以被其他类访问。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">void 表示该方法没有返回值。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">methodName 表示该方法的名称。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">parameterType 表示该方法的参数类型，可以是任何基本数据类型、对象类型或数组类型。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">parameterName 表示该方法的参数名称。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">method body 表示该方法的具体实现。</p></li></ul><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">例如，以下是一个有参数无返回值的方法的示例：</p><pre class="brush:as3;toolbar:false">public void printMessage(String message) { System.out.println(message); }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，printMessage 方法接收一个字符串作为参数，并将其打印到控制台上。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">可以通过以下方式调用这个方法：</p><pre class="brush:as3;toolbar:false">printMessage("Hello, world!");</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，我们调用 printMessage 方法并将字符串 "Hello, world!" 作为参数传递给它。printMessage 方法将该字符串打印到控制台上，然后返回。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">需要注意的是，参数列表必须与方法定义中的参数类型和数量匹配，否则会导致编译时错误。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">有参数无返回值的方法在Java中非常常见。通过将数据作为参数传递给方法，可以在方法中执行一些操作，例如打印消息、修改对象状态等。这种方法通常用于执行操作而不需要返回结果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，无参数有返回值的方法是指在调用方法时不需要传递任何参数，但该方法在执行完成后返回一个值。该值可以是任何基本数据类型、对象类型或数组类型。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">定义无参数有返回值的方法的语法如下：</p><pre class="brush:as3;toolbar:false">public returnType methodName() { // method body return returnValue; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">其中：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><ul class=" list-paddingleft-2" style="list-style-type: disc;"><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">public 表示该方法是公共的，可以被其他类访问。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnType 表示该方法的返回类型，可以是任何基本数据类型、对象类型或数组类型。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">methodName 表示该方法的名称。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">method body 表示该方法的具体实现。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnValue 表示该方法的返回值。</p></li></ul><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">例如，以下是一个无参数有返回值的方法的示例：</p><pre class="brush:as3;toolbar:false">public int getRandomNumber() { Random random = new Random(); return random.nextInt(100); }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，getRandomNumber 方法不接收任何参数，并使用 Random 类生成一个 0 到 99 之间的随机整数，并将其作为返回值返回。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">可以通过以下方式调用这个方法：</p><pre class="brush:as3;toolbar:false">int randomNumber = getRandomNumber(); System.out.println(randomNumber); // 输出随机数</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，我们调用 getRandomNumber 方法，该方法返回一个随机整数。然后将该值存储在 randomNumber 变量中，最后使用 System.out.println() 方法输出结果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">需要注意的是，返回值必须与方法定义中的返回类型相匹配，否则会导致编译时错误。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">无参数有返回值的方法在Java中非常常见。通过从方法中返回数据，可以使代码更灵活、可重用，并使其更易于维护。例如，在某些情况下，您可能需要从方法中获取某些值，但不需要传递任何参数。此时，无参数有返回值的方法将非常有用。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，方法是一段代码块，用于执行特定任务。方法通常接收零个或多个参数，并可以返回一个值或不返回任何值。定义方法的语法如下：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><pre class="brush:as3;toolbar:false">modifier returnType methodName(parameterList) { // method body return returnValue; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">其中：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">modifier：修饰符，用于定义方法的访问权限。常用的访问权限修饰符有 public、private 和 protected，其中 public 表示该方法可以被其他类访问，private 表示该方法只能被当前类访问，protected 表示该方法可以被当前类和其子类访问。</p><ul class=" list-paddingleft-2" style="list-style-type: disc;"><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnType：方法的返回值类型，可以是基本数据类型、对象类型或数组类型。如果方法不返回任何值，则返回类型为 void。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">methodName：方法名称，用于标识方法。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">parameterList：参数列表，用于传递给方法的数据。参数列表由一组参数类型和参数名称组成，多个参数之间用逗号分隔。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">method body：方法体，包含方法的实际代码逻辑。</p></li><li><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">returnValue：方法的返回值，用于返回方法执行结果。如果方法不返回任何值，则可以省略 return 语句。</p></li></ul><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">例如，以下是一个计算两个整数之和的方法定义：</p><pre class="brush:as3;toolbar:false">public int sum(int a, int b) { int result = a + b; return result; }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，sum 方法接收两个整数作为参数，并将它们相加。最后，该方法返回计算结果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">可以通过以下方式调用这个方法：</p><pre class="brush:as3;toolbar:false">int a = 10; int b = 20; int result = sum(a, b); System.out.println(result);</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在这个示例中，我们调用 sum 方法，并将 a 和 b 作为参数传递给它。该方法将这两个值相加，并返回计算结果。然后，我们将结果存储在 result 变量中，并使用 System.out.println() 方法将其输出到控制台上。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p3" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "PingFang SC"; white-space: normal;">需要注意的是，方法定义必须在类中进行，而不能在另一个方法中定义。另外，方法名称应该能够准确地反映方法的功能和目的，以便代码更易于理解和维护。</p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">下面是一个Java中的数组综合案例，实现了对学生成绩的统计和分析。</p><pre class="brush:as3;toolbar:false">import java.util.Scanner; public class ScoreAnalysis { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.print("请输入学生人数："); int count = scanner.nextInt(); int[] scores = new int[count]; int sum = 0; for (int i = 0; i < count; i++) { System.out.print("请输入第" + (i + 1) + "个学生的成绩："); int score = scanner.nextInt(); scores[i] = score; sum += score; } double average = sum * 1.0 / count; System.out.println("总分：" + sum); System.out.println("平均分：" + average); System.out.println("最高分：" + findMax(scores)); System.out.println("最低分：" + findMin(scores)); System.out.println("及格人数：" + countPass(scores)); } public static int findMax(int[] scores) { int max = scores[0]; for (int i = 1; i < scores.length; i++) { if (scores[i] > max) { max = scores[i]; } } return max; } public static int findMin(int[] scores) { int min = scores[0]; for (int i = 1; i < scores.length; i++) { if (scores[i] < min) { min = scores[i]; } } return min; } public static int countPass(int[] scores) { int count = 0; for (int i = 0; i < scores.length; i++) { if (scores[i] >= 60) { count++; } } return count; } }</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">该程序首先从用户输入中获取学生人数，然后创建一个具有指定大小的整数数组，用于存储学生的成绩。接下来，程序依次获取每个学生的成绩，并将其存储在数组中。然后，程序使用一些方法来分析这些成绩，包括计算总分、平均分、最高分、最低分以及及格人数。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">其中，findMax 方法用于查找数组中的最大值，findMin 方法用于查找数组中的最小值，countPass 方法用于计算及格的学生人数。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">这个案例展示了如何在Java中使用数组和方法来实现复杂的计算和分析任务。通过定义适当的方法，可以使代码更加模块化和可维护，提高代码的重用性和可读性。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，数组的大小是固定的，一旦创建，就不能直接改变它的大小。但是，我们可以通过删除数组中的元素来实现删除的效果。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">删除数组中的元素的一般方法是创建一个新的数组，并将要保留的元素复制到新数组中。以下是一些实现删除数组元素的方法：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用 System.arraycopy() 方法：</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">这是一个Java内置的方法，可以使用它来复制数组元素。我们可以通过将要保留的元素复制到一个新数组中来删除数组元素。例如，要从以下数组中删除第三个元素：</p><pre class="brush:as3;toolbar:false">int[] arr = {1, 2, 3, 4, 5}; int[] newArr = new int[arr.length-1]; System.arraycopy(arr, 0, newArr, 0, 2); System.arraycopy(arr, 3, newArr, 2, 2);</pre><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">上面的代码中，我们首先创建一个新数组newArr，其大小比原数组arr小1。然后，我们使用System.arraycopy()方法将arr中的前两个元素复制到newArr中，然后将arr中的第四和第五个元素复制到newArr中的第三个和第四个位置。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用ArrayList类：</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">另一种方法是使用Java中的ArrayList类。它是一个动态数组，可以在运行时添加或删除元素。我们可以将数组转换为ArrayList，并使用remove()方法从中删除元素。例如，要从以下数组中删除第三个元素：</p><pre class="brush:as3;toolbar:false">int[] arr = {1, 2, 3, 4, 5}; List<Integer> list = new ArrayList<Integer>(Arrays.asList(arr)); list.remove(2); arr = list.stream().mapToInt(i -> i).toArray();</pre><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在上面的代码中，我们首先将arr数组转换为ArrayList，并使用remove()方法删除第三个元素。然后，我们将ArrayList转换回数组。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">注意：这种方法需要使用Java 8或更高版本。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用Java 8的Stream API：</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用Java 8的Stream API，我们可以轻松地过滤掉数组中的元素。例如，要从以下数组中删除第三个元素：</p><pre class="brush:as3;toolbar:false">int[] arr = {1, 2, 3, 4, 5}; int[] newArr = IntStream.range(0, arr.length).filter(i -> i != 2).map(i -> arr[i]).toArray();</pre><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在上面的代码中，我们首先使用IntStream.range()方法创建一个整数范围流，该流包含数组的索引。然后，我们使用filter()方法过滤掉第三个元素的索引，并使用map()方法将剩余的元素映射到新数组中。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">无论使用哪种方法，删除数组中的元素都需要创建一个新的数组。因此，如果需要频繁删除元素，则建议使用ArrayList。如果需要对数组进行少量的更改，则可以使用System.arraycopy()方法或Java 8的Stream API。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在Java中，数组的大小是固定的，一旦创建，就不能直接改变它的大小。但是，我们可以通过创建一个新的数组，并将新的元素添加到其中来实现数组添加元素的效果。以下是一些实现在Java中数组添加元素的方法：</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用 Arrays.copyOf() 方法：</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">这是一个Java内置的方法，可以使用它来创建一个新的数组，并将原始数组中的所有元素复制到新数组中。例如，要向以下数组中添加一个新元素：</p><pre class="brush:as3;toolbar:false">int[] arr = {1, 2, 3, 4, 5}; int[] newArr = Arrays.copyOf(arr, arr.length + 1); newArr[newArr.length - 1] = 6;</pre><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">上面的代码中，我们首先使用Arrays.copyOf()方法创建一个新数组newArr，它比原始数组arr长1。然后，我们将原始数组arr中的所有元素复制到newArr中，并将新元素6添加到newArr的末尾。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">使用 ArrayList 类：</p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">另一种方法是使用 Java 中的 ArrayList 类。它是一个动态数组，可以在运行时添加或删除元素。我们可以将数组转换为 ArrayList，并使用 add() 方法向其中添加新元素。例如，要向以下数组中添加一个新元素：</p><pre class="brush:as3;toolbar:false">int[] arr = {1, 2, 3, 4, 5}; List<Integer> list = new ArrayList<Integer>(Arrays.asList(arr)); list.add(6); arr = list.stream().mapToInt(i -> i).toArray();</pre><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">在上面的代码中，我们首先将 arr 数组转换为 ArrayList，并使用 add() 方法向其中添加新元素 6。然后，我们将 ArrayList 转换回数组。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">注意：这种方法需要使用 Java 8 或更高版本。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p1" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; white-space: normal;">无论使用哪种方法，添加元素都需要创建一个新的数组。因此，如果需要频繁添加元素，则建议使用 ArrayList。如果需要对数组进行少量的更改，则可以使用 Arrays.copyOf() 方法。</p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p class="p2" style="margin-top: 0px; margin-bottom: 0px; font-variant-numeric: normal; font-variant-east-asian: normal; font-stretch: normal; font-size: 15px; line-height: normal; font-family: "Helvetica Neue"; min-height: 17px; white-space: normal;"><br/></p><p><br/></p>
<p>Java中数组相关的异常有以下几种：</p><ol style="border: 0px solid rgb(217, 217, 227); box-sizing: border-box; --tw-border-spacing-x:0; --tw-border-spacing-y:0; --tw-translate-x:0; --tw-translate-y:0; --tw-rotate:0; --tw-skew-x:0; --tw-skew-y:0; --tw-scale-x:1; --tw-scale-y:1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; --tw-scroll-snap-strictness:proximity; --tw-ordinal: ; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; --tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width:0px; --tw-ring-offset-color:#fff; --tw-ring-color:rgba(59,130,246,0.5); --tw-ring-offset-shadow:0 0 transparent; --tw-ring-shadow:0 0 transparent; --tw-shadow:0 0 transparent; --tw-shadow-colored:0 0 transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; --tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; --tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; --tw-backdrop-brightness: ; --tw-backdrop-contrast: ; --tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; --tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: ; --tw-backdrop-sepia: ; list-style-position: initial; list-style-image: initial; margin-top: 1.25em; margin-bottom: 1.25em; padding: 0px 0px 0px 1rem; counter-reset: item 0; display: flex; flex-direction: column; color: rgb(55, 65, 81); font-family: Söhne, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, Cantarell, "Noto Sans", sans-serif, "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"; white-space: pre-wrap; background-color: rgb(247, 247, 248);" class=" list-paddingleft-2"><li><p>数组越界异常(ArrayIndexOutOfBoundsException)：当尝试访问数组中不存在的索引时抛出此异常，即索引值小于 0 或大于等于数组长度。</p></li><li><p>空指针异常(NullPointerException)：当尝试对空对象或空数组进行操作时抛出此异常。例如，如果一个数组变量为 null，那么尝试访问该数组的任何元素都会抛出空指针异常。</p></li><li><p>类型不匹配异常(ArrayStoreException)：当尝试将不兼容的类型存储到数组中时抛出此异常。</p></li><li><p>非法参数异常(IllegalArgumentException)：当尝试传递无效的参数给数组的某些方法时抛出此异常。例如，如果尝试创建长度为负数的数组，则会抛出非法参数异常。</p></li><li><p>超出最大数组长度异常(NegativeArraySizeException)：当尝试创建一个负数长度的数组时，会抛出此异常。</p></li></ol><p>这些异常通常与数组操作相关，需要在代码中进行合适的处理，以避免程序崩溃。通常的处理方式是使用 try-catch 块来捕获并处理异常。</p><p><br/></p>
<p>在Java中获取数组的最大值有多种方式，下面列举其中几种常用的方法：</p><p><br/></p><p>1.使用for循环遍历数组，逐个比较数组元素的大小，找出最大值：</p><p><br/></p><pre class="brush:as3;toolbar:false">public static int findMax(int[] arr) { int max = arr[0]; for (int i = 1; i < arr.length; i++) { if (arr[i] > max) { max = arr[i]; } } return max; }</pre><p>2.使用Java 8中的Stream流API，将数组转换成流，然后使用max()方法查找最大值：</p><p><br/></p><pre class="brush:as3;toolbar:false">public static int findMax(int[] arr) { return Arrays.stream(arr).max().getAsInt(); }</pre><p>3.使用Java 8中的IntStream.range()方法和reduce()方法，将数组转换成IntStream，然后使用reduce()方法查找最大值：</p><p><br/></p><pre class="brush:as3;toolbar:false">public static int findMax(int[] arr) { return IntStream.range(0, arr.length).map(i -> arr[i]).reduce(Integer.MIN_VALUE, Math::max); }</pre><p>4.使用Java 8中的Arrays类的sort()方法将数组排序，然后获取最后一个元素的值即为最大值：</p><p><br/></p><pre class="brush:as3;toolbar:false">public static int findMax(int[] arr) { Arrays.sort(arr); return arr[arr.length-1]; }</pre><p>需要注意的是，如果数组为空数组，调用以上方法时都会抛出ArrayIndexOutOfBoundsException异常。因此在使用这些方法时，需要先判断数组是否为空，例如：</p><p><br/></p><pre class="brush:as3;toolbar:false">if (arr == null || arr.length == 0) { throw new IllegalArgumentException("数组不能为空"); }</pre><p><br/></p>