1.学习封装

package com.msb.test07;
//封装
public class Girl {
    private int age;
//    赋值
    public void setAge(int age){
        if(age > 30){
            this.age = 18;
        }else{
            this.age = age;
        }
    }
//    读取
    public int getAge(){
        return age;
    }
}

package com.msb.test07;

public class Test {
    public static void main(String[] args) {
        Girl girl = new Girl();
        girl.setAge(28);
        System.out.println(girl.getAge());
    }
}