java 封装和隐藏 权限修饰符

Posted 2022-11-23 DQ_CODING

概念

问题的引入

封装性的体现

权限修饰符

案例

package lesson.l11_oop2;

/**
 * Illustration
 *
 * @author DengQing
 * @version 1.0
 * @datetime 2022/7/3 15:28
 * @function
 */
public class Person 
    private int age;

    public void setAge(int age) 
/*        if (age<0||age>130)
            throw new RuntimeException("传入的数据非法");
        
        this.age=age;*/
        if (age >= 0 && age <= 130) 
            this.age = age;
         else 
//            this.age = 0;
            throw new RuntimeException("传入的数据非法");
        
    

    public int getAge() 
        return this.age;
    


class PersonTest 
    public static void main(String[] args) 
        Person person = new Person();
        person.setAge(-9);
        System.out.println(person.getAge());