测试类。。。重写篇

package com.c2;

public class Ext {
	public static void main(String[] args) {

		Student s = new Student();
		System.out.println(s.name);
		System.out.println(s.age);
	}

}


package com.c2;

public class Person {
	int age;
	String name = "zhangsan";

	Person() {
	}

	public Person(int a) {
		age = a;
	}

}


package com.c2;

public class Student extends Person {
	public Student() {
	}

	public Student(int a) {
		super(23);
	}

}

　　总结：构造函数必须带着，重写发生在子类继承父类里，继承是子类调用父类的属性或方法，重写时方法名称，及参数列表都得相同，但方法体内容不相同，super关键字是调用父类里的方法