繼承的必要性

以富二代和富一代刷卡爲例說明類的繼承的必要性


兩段代碼存在大量的重複，代碼冗餘需要避免，對開發也不利。


引入類的繼承

package classq;

public class Rich {
protected String name;
protected int age;
protected String sex;
public Rich(int age,String name,String sex) {
	//形參與成員名字重名，用 this 來區分：
	this.age=age;
	this.name=name;
	this.sex=sex;
}
public void shuaKa()
{
	System.out.println("喜刷刷，喜刷刷。。。");
}
}

package classq;

public class Rich1st2 extends Rich{
public Rich1st2(int age,String name,String sex) {
	super(age,name,sex);//調用父類構造函數
}
public void shuaKa(){
	System.out.println(this.name+"掏出自己的卡");
	super.shuaKa();//調用父類放大
}
}

package classq;

public class Rich2nd2 extends Rich{
public Rich2nd2(int age,String name,String sex) {
	super(age,name,sex);//調用父類構造函數
}
public void shuaKa(){
	System.out.println(this.name+"掏出爸爸的卡");
	super.shuaKa();//調用父類放大
}
}

package classq;

public class RichMain {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Rich A = new Rich(18,"cma","男");
		A.shuaKa();
		A=new Rich2nd2(18,"cma","男");
		A.shuaKa();
		A=new Rich1st2(18,"cma","男");
		A.shuaKa();
		}

}