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