值传递和地址传递

目录

值传递

package com.zhang.parameter;
//值传递
public class MethodDemo1 {
    public static void main(String[] args) {
        int a = 10;
        System.out.println(a);

        System.out.println("~~~~~~~~~~~~~~~");
        change(a);//无论你传入的是什么 最后输出的都是330
        System.out.println(a);


    }
    public static int change(int num){
        System.out.println(num);
        num = 330;
        System.out.println(num);
        return num;
    }
}

地址传递

package com.zhang.parameter;
/*
* 地址传递
* */
public class MethodDemo2 {
    public static void main(String[] args) {
        int[] arr = {10,20,30,40,50};
        System.out.println(arr[0]);
        System.out.println("~~~~~~~~~~~~~~~~");
        change(arr);

    }

    public static void change(int[] arr){
        System.out.println(arr[0]);
        arr[0] = 30;
        System.out.println(arr[0]);
    }
}