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:1823