static

发布时间 2023-09-24 16:02:45作者: 翻斗花园小美Q

1、成员变量按照有无static修饰,分为两种

  类变量:有static修饰,属于类,在计算机里只有一份,会被类的全部对象共享

  实例变量(对象的变量):无static修饰,属于每个对象的

public class Student(){
    //类变量
    static String name;  //有static修饰,属于类,会被类的全部对象共享
    int age;
}

 例子:


package d1_staticdemo;

//另一个类(前提)
public class Student {
static String name;
int age;
}
public class Test {
    public static void main(String[] args) {
        Student.name = "青柠";

        Student s1 = new Student();
        s1.name = "娜娜";

        Student s2 = new Student();
        s2.name = "xx";

        //System.out.println(Student.name);
        System.out.println(s1.name);
        System.out.println(s2.name);


    }
}    //输出结果都是xx
//实例变量的用法
        s1.age = 18;
        s2.age = 23;
        System.out.println(s1.age);
        System.out.println(s2.age);

输出结果:18
        23