Author: vietnam1992

  • Tuần 8: Giao diện (interface)

    [codes=java]import java.util.*;import java.io.*; interface HINH{  public final double PI=3.14;  public void Nhap();  public void Xuat();  public float Dientich();  } class HINHVUONG implements HINH{  private float canh;  public void Nhap()  {    Scanner x=new Scanner(System.in);    System.out.print("NHap canh cho hinh vuong: ");    canh=x.nextFloat();  }  public void Xuat()  {    System.out.println("Hinh vuong co canh vua nhap la:" +canh);      }  public float Dientich()  {    return canh*canh;  }} class HCN implements HINH{  private float dai;  private float rong;  public void Nhap()  {    Scanner x=new Scanner(System.in);    System.out.print("Nhap chieu dai…