Java静态static关键字修饰成员变量

// 静态static关键字修饰成员变量

如果一个成员变量使用了static关键字，那么这个变量不再属于对象自己，而是属于所在的类。多个对象共享同一份数据。

public cllas Demo01StaticField { public static void main(String[] args) { Student one = new Student( name: "汤姆", age: 19); one.room = "110办公室"; System.out.println("姓名：" + one.getName() + "，年龄：" + one.getAge() + "，房间：" + one.room + "，编号：" + one.getId());

Student two = new Student( name: "杰瑞", age: 18); System.out.println("姓名：" + two.getName() + "，年龄：" + two.getAge() + "，房间：" + two.room + "，编号：" + two.getId());

} }

public class Student { private int id; // 编号 private String name; // 姓名 private int age; // 年龄 static String room; // 所在房间 private static int idCounter = 0; // 编号计数器，每当new了一个新对象的时候，计数器++

public Student() { this.id = ++idCounter; }

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

public int getId() { return id; }

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

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; } }