【java】封装与构造器

package 封装;

public class Day1 {
    private int age;
    private String name;

    public void setAge(int age){
        if(age < 0 || age > 100){           //安全控制，防止年龄输入不正常。
            System.out.println("error");
        }
        this.age = age;
    }
    public int getAge(){
        return age;
    }

    public void setName(String name){

        this.name = name;
    }
    public String getName(){
        return name;
    }


}

Test:

public class Test {
    public static void main(String[] args){
        Day1 user = new Day1();

        user.setAge(50);
        user.setName("yh");

        System.out.println(user.getAge());
        System.out.println(user.getName());
    }
}

构造方法：

package 构造方法;

public class Dwy {
    
    public Dwy(){
        System.out.println("缺省构造器");
        
    }
    public Dwy(int a){
        System.out.println("带参数构造器");
    }
}

Test:

public class Test1 {
    public static void main(String[] args){

        Dwy u = new Dwy();
        Dwy u1 = new Dwy(10);
    }
}