Java面向对象-方法的值传递和引用传递

package com.java1234.chap03.sec03;
public class Person {
    void speak(int age){
        System.out.println("我今年"+age+"岁了");
        age=24; // 作用范围是方法里
    }
    public static void main(String[] args) {
        Person xiaoli=new Person();
        int age=23;
        xiaoli.speak(age);
        System.out.println(age);
    }
}

package com.java1234.chap03.sec03;
class SanWei{
    int b; // 胸围
    int w; // 腰围
    int h; // 腿围
}
public class Person {
    void speak(int age,SanWei sanWei){
        System.out.println("我今年"+age+"岁了，我的三围是："+sanWei.b+","+sanWei.w+","+sanWei.h);
        age=24; // 作用范围是方法里
        sanWei.b=80; // 胸围改成80
    }
    public static void main(String[] args) {
        Person xiaoli=new Person();
        int age=23;
        SanWei sanWei=new SanWei();
        sanWei.b=90;
        sanWei.w=60;
        sanWei.h=90;
        // age传递的是值 ，sanWei是对象，传递的是引用(地址,c里叫指针)
        xiaoli.speak(age,sanWei);
        System.out.println(age);  
        System.out.println(sanWei.b);
    }
}