类与对象的创建

//学生类
public class Student {
    //属性：字段
    String name;//null
    int age;//0
    //方法
    public void  say(){
        System.out.println(this.name+"在学习");
    }


}

public class Application {
    public static void main(String[] args) {
        //类是抽象的，类实例化后会返回一个自己的对象
        //student对象就是Student类的具体实例
        Student xiaoming = new Student();
        Student xiaohong = new Student();

        xiaoming.name="小明";
        xiaoming.age=3;
        System.out.println(xiaoming.name);//小明
        System.out.println(xiaoming.age);//3

        xiaohong.name="小红";
        xiaohong.age=3;
        System.out.println(xiaohong.name);//小红
        System.out.println(xiaohong.age);//3
        xiaoming.say();
    }

}