Bài viết Một số bài tập Java Căn bản

Tích 2 số

Mã:

/**
 * @(#)tich.java
 *
 *
 * @author
 * @version 1.00 2011/1/18
 */
import java.util.Scanner;
public class tich {

    /**
     * Creates a new instance of <code>tich</code>.
     */
    public tich() {
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s = new Scanner(System.in);
        int a = s.nextInt();
       int b = s.nextInt();
        int c = a*b;
        System.out.print("tong la:"+c);
}
}

Tính Tổng

Mã:

import java.util.Scanner;
public class Tinhtong {

    /**
     * Creates a new instance of <code>songuyen</code>.
     */
    public Tinhtong() {
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner s = new Scanner(System.in);
        int a = s.nextInt();
        int b = s.nextInt();
        int c = a+b;
        System.out.print("tong la:"+c);


    }
}

Số nguyên tố

Mã:

/**
 * @(#)songuyento.java
 *
 *
 * @author 
 * @version 1.00 2011/1/18
 */
import java.util.*;
public class songuyento {
        
    /**
     * Creates a new instance of <code>songuyento</code>.
     */
    public songuyento() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        int i,s=0;
        Scanner a=new Scanner(System.in);
        int n=a.nextInt();
       if (n==0||n==1)
       { System.out.print(n+" ko phai la so nguyen to");return;}
        if(n==2)
        {System.out.print(n+" la so nguyen to");return;}
        for(i=2;i<=n/2;i++)
           if(n % i == 0) 
           {s=1;
           break;}
         if(s==0)
           System.out.print(n+" la so nguyen to");
            else  
            System.out.print(n+" ko phai la so nguyen to");
         
        
        
    }
}

Dãy fibonaxi

Mã:

/**
 * @(#)fibonaci.java
 *
 *
 * @author
 * @version 1.00 2011/1/18
 */
import java.util.*;

public class fibonaci {

    /**
     *  Day fibonaci
     */
     public static int nhap() 
       {
           Scanner s= new Scanner(System.in);
           boolean check=false;
           int n=0;
           return(n);
    }
     static boolean kt_fibo(int n)
    {
        boolean kt=true;
        if(n<=1)
            return false;
            
 int f1=1,f2=1,fi=2;
while(!false)
 {
     int t=f1;
     f1=f2;
     f2=t+f2;
     kt=false;
    break;
  }
            return kt;
  
}
    public static void main(String[] args) {
 Scanner s=new Scanner(System.in);
 System.out.println("Nhap bao nhieu phan tu cua mang ");
   //Nhap so luong phan tu
    int k = s.nextInt();
     int [] dayso; //khai bao mang
    dayso = new int [100];
    System.out.println("Nhap mang ");
    for(int i=0;i<=k-1;i++)
    {
        System.out.println("Nhap so phan tu thu " +  i);
            dayso [i]= nhap();
    }
    
    //Xuat mang
    System.out.println("Cac phan tu la so fibonaci cua mang ");
    for(int i =0;i<=k-1;i++){
            if(kt_fibo(dayso[i]))
            System.out.println("So " + dayso [i] + " la so fibonaci");
            else 
                System.out.println("So " + k + " khong phai la so fibo");
    
    }
}
}

Chu vi, diện tích

Mã:

import java.util.scanner;
class BAI1 {
      public static void main(String[] args)
    {
       Scanner s = new Scanner(System.in);
        float pi=3.14;
        float a = r.nextInt();
        system.out.println("nhap vao ban kinh r :");
        double cv=2*pi*r;
        double dt=pi*r*r;
        system.out.println("chu vi la :"+cv);
        system.out.println("dien tich la :" +dt);
    }
}

Tham khảo thêm tại đây
[NOTE]http://www.mediafire.com/?k77i6fsfjged998[/NOTE]