封装

封装

-   提高程序安全性，保护数据
-   隐藏代码的实现细节
-   统一接口
-   系统可维护性增加

public class APPlication {
    public static void main(String[] args) {
        Student s1 = new Student();
        s1.setName("Duncan");
        System.out.println(s1.getName());
    }
}

public class Student {
    private String name;
    private int Number;
    private char sex;

    private int age;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        if (age > 120 || age < 0){
            this.age = 3;
        }else {
            this.age = age;
        }
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getNumber() {
        return Number;
    }

    public void setNumber(int number) {
        Number = number;
    }

    public char getSex() {
        return this.sex;
    }

    public void setSex(char gener) {
        this.sex = gener;
    }
}