类的继承 super关键字

package expression;

public class Computer {
	String SayHellow(){
		return "welcome";
	}
}

package expression;

public class Pad extends Computer{
	String SayHellow(){
		return "welcome"+"平板电脑";
	}
}

package expression;

public class Pad extends Computer{
	String SayHellow(){
		return super.SayHellow()+"平板电脑";
	}
}

package expression;

public class Pad extends Computer{

	public Pad(){
		//初始化
		super();//调用父类的构造方法
	}
	
	String SayHellow(){
		//调用父类的成员方法
		return super.SayHellow()+"平板电脑";
	}

}

package expression;

public class Pad extends Computer{

	public Pad(){
		//调用父类的属性
		this.screen = super.screen;//this 和super 是一样的，只不过this是本类，super是父类
	}
	
	String SayHellow(){
		//调用父类的成员方法
		return super.SayHellow()+"平板电脑";
	}

}