继承

/*子类继承了父类的属性和方法*/
 class Person{
	 String name;
	String sex;
	int age;
	void speak(){
		System.out.println("这是person说话的方法");
	}
}
public class Student extends Person{
    int num;
    void speak(){
    	System.out.println("这是stu说话的方法");
    }
	public static void main(String[] args) {
    Student stu=new Student();
    stu.name="liu";
    stu.speak();
    System.out.println(stu.name);
	}

}