方法的参数传递

package com.itheuma_03;

public class ArrayTest08 {
    public static void main(String[] args) {
        int[] arr = {10, 20, 30};
        System.out.println("change前" + arr[1]);
        change(arr);
        System.out.println("change后" + arr[1]);
    }

    //对于引用类型的参数，形式参数的改变，影响实际参数的值
    public static void change(int[] arr) {
        arr[1] = 200;
    }
}

E:\environment\java\jdk1.8\bin\java.exe "-javaagent:E:\Program Files\IntelliJ IDEA 2020.1.1\lib\idea_rt.jar=62831:E:\Program Files\IntelliJ IDEA 2020.1.1\bin" -Dfile.encoding=UTF-8 -classpath 08
change前20
change后200

Process finished with exit code 0

 

package com.itheuma_03;

public class ArrayTest07 {
    public static void main(String[] args) {
        int number = 100;
        System.out.println("change前" + number);
        change(number);
        System.out.println("change后" + number);
    }

    //对于基本数据类型，形式参数的改变，不影响实际参数的值
    public static void change(int number) {
        number = 200;
    }
}

E:\environment\java\jdk1.8\bin\java.exe "-javaagent:E:\Program Files\IntelliJ IDEA 2020.1.1\lib\idea_rt.jar=62871:E:\Program Files\IntelliJ IDEA 2020.1.1\bin" -Dfile.encoding=UTF-8 -classpath 
change前100
change后100

Process finished with exit code 0