143/144静态static关键字概述和修饰成员变量

静态static关键字概述

静态static关键字修饰成员变量

public class Student {
    private int id;
    private String name;
    private int age;

    static String room;//锁在教室

    private static int idCount = 0;//学号计数器，每当new了一个新对象的时候，计数器++


    public Student(String name, int age) {
        this.name = name;
        this.age = age;
        this.id = idCount++;
    }

    public Student() {
        idCount++;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

public class test {
    public static void main(String[] args) {
        Student two = new Student("黄蓉",19);
        two.room="111教室";
        System.out.println("姓名："+two.getName()+"年龄："+two.getAge()+"教室："+two.room+"学号:"+two.getId());

        Student one = new Student("郭靖",19);
        System.out.println("姓名："+one.getName()+"年龄："+one.getAge()+"教室："+one.room+"学号:"+one.getId());
    }