java （1）定义抽象类People，包括两个属性：name，sex；一个抽象方法void sayHello();

发布网友发布时间：2022-05-23 23:04

共2个回答

热心网友时间：2024-03-09 22:24

People.java:
package util;

public abstract class People {
private String name;
private String sex;

abstract void sayHello();
}

ChinaPeople.java:
package util;

public class ChinaPeople extends People {

@Override
void sayHello() {
System.out.println("会使用方法的override");
}

}
AmericanPeople.java:
package util;

public class AmericanPeople extends People{

@Override
void sayHello() {
System.out.println("会使用抽象类");
}

}
BeijingPeople.java:
package util;

public class BeijingPeople extends ChinaPeople {

@Override
void sayHello() {
System.out.println("会使用三层的继承");
}

}
main:
public static void main(String[] args) {
BeijingPeople beijingPeople = new BeijingPeople();
AmericanPeople americanPeople = new AmericanPeople();
ChinaPeople chinaPeople = new ChinaPeople();
americanPeople.sayHello();
chinaPeople.sayHello();
beijingPeople.sayHello();
}
结果：
会使用抽象类
会使用方法的override
会使用三层的继承

热心网友时间：2024-03-09 22:24

public abstract class People {

public String name;
public String sex;

public abstract void sayHello();
}

public class ChinesePeople extends People {

@Override
public void sayHello() {
// TODO Auto-generated method stub
System.out.println("Hello, I am a Chinese...");
}

}

public class AmericanPeople extends People {

@Override
public void sayHello() {
// TODO Auto-generated method stub
System.out.println("Hello, I am an American...");
}

}

public class BeijingPeople extends ChinesePeople {

public void sayHello(){
System.out.println("Hello, I am beijing er...");
}
public static void main(String[] args) {
ChinesePeople cp = new ChinesePeople();
cp.sayHello();
AmericanPeople ap = new AmericanPeople();
ap.sayHello();
BeijingPeople bjp = new BeijingPeople();
bjp.sayHello();
}
}

输出：

Hello, I am a Chinese...
Hello, I am an American...
Hello, I am beijing er...