Chương 4-Bài 9. Lớp trừu tượng (Abstract class)

Lớp trừu tượng (abstract class) và hàm trừu tượng (abstract method)

Ví dụ 1:

package com.nentang.vn;

public abstract class ConVat {
  public String ten;
  public int tuoi;
  public boolean gioi_tinh;
  public float so_chan;
  public float can_nang;
  
  abstract void Keu();
  
  public void chay_nhay() {
    System.out.println("ConVat dang chay nhay!");
  }
}

public class Cho extends ConVat {
  @Override
  public void Keu() {
    System.out.println("Gau gau!");
  }	
}

public class Meo extends ConVat {
  @Override
  public void Keu() {
    System.out.println("Meoo meoo!");
  }
}

Ví dụ 2:

abstract class Bike {  
    abstract void run();  
}  

class Honda extends Bike {  
    void run() {
        System.out.println("running safely..");
    }
 
    public static void main(String args[]) {  
        Bike obj = new Honda();  
        obj.run();  
    }  
}