An assortment of programming examples covering many different topics. Many searchable collection of source code snippets illustrating specific tasks best coding practices. With our programming samples you will be able to add your own functionality to the already existing sample. All the examples are made available here for you to copy and paste into your programs.


Free Java Source Code Links

1. Core Java Programs [PAGE 1]

2. Core Java Programs [PAGE 2]

3. Core Java Programs [PAGE 3]

4. Date Utility Code Snippet

5. String Utility Code Snippet

Core Java Programs [PAGE 3]

Some Java programs which help lot of java beginners to understand the basic fundamentals in Java programming. Most of these programs take input from the command line. Ex - int num = Integer.parseInt(args[0]);

Program 20

/* switch case demo

   Example :

           Input - 124

           Output - One Two Four */

 

class SwitchCaseDemo{

      public static void main(String args[]){

          try{

          int num = Integer.parseInt(args[0]);

          int n = num; //used at last time check

          int reverse=0,remainder;

          while(num > 0){

                remainder = num % 10;

                reverse = reverse * 10 + remainder;

                num = num / 10;

           }

          String result=""; //contains the actual output

          while(reverse > 0){

               remainder = reverse % 10;

               reverse = reverse / 10;

               switch(remainder){

                    case 0 :

                             result = result + "Zero ";

                             break;

                    case 1 :

                             result = result + "One ";

                             break;

                    case 2 :

                             result = result + "Two ";

                             break;

                    case 3 :

                             result = result + "Three ";

                             break;

                    case 4 :

                             result = result + "Four ";

                             break;

                    case 5 :

                             result = result + "Five ";

                             break;

                    case 6 :

                             result = result + "Six ";

                             break;

                    case 7 :

                             result = result + "Seven ";

                             break;

                    case 8 :

                             result = result + "Eight ";

                             break;

                    case 9 :

                             result = result + "Nine ";

                             break;

                    default:

                             result="";

                 }

            }

                System.out.println(result);

        }catch(Exception e){

             System.out.println("Invalid Number Format");

         }

     }

}


Program 21

/* Write a program to generate Harmonic Series.

   Example :

           Input - 5

           Output - 1 + 1/2 + 1/3 + 1/4 + 1/5 = 2.28 (Approximately) */

class HarmonicSeries{

      public static void main(String args[]){

      int num = Integer.parseInt(args[0]);

      double result = 0.0;

      while(num > 0){

            result = result + (double) 1 / num;

            num--;

      }

      System.out.println("Output of Harmonic Series is "+result);

  }

}


Program 22

/*Write a program to find average of consecutive N Odd no. and Even no. */

class EvenOdd_Avg{

      public static void main(String args[]){

      int n = Integer.parseInt(args[0]);

      int cntEven=0,cntOdd=0,sumEven=0,sumOdd=0;

      while(n > 0){

           if(n%2==0){

               cntEven++;

               sumEven = sumEven + n;

           }

           else{

               cntOdd++;

               sumOdd = sumOdd + n;

           }

           n--;

      }

      int evenAvg,oddAvg;

      evenAvg = sumEven/cntEven;

      oddAvg = sumOdd/cntOdd;

      System.out.println("Average of first N Even no is "+evenAvg);

      System.out.println("Average of first N Odd no is "+oddAvg);

 

  }

}


Program 23

/* Display Triangle as follow : BREAK DEMO.

    1

    2 3

    4 5 6

    7 8 9 10 ... N */

class Output1{

      public static void main(String args[]){

          int c=0;

          int n = Integer.parseInt(args[0]);

         loop1: for(int i=1;i<=n;i++){

         loop2: for(int j=1;j<=i;j++){

                       if(c!=n){

                            c++;

                            System.out.print(c+" ");

                       }

                       else

                           break loop1;

                    }

                    System.out.print("\n");

                 }

     }

}


Program 24

/* Display Triangle as follow

    0

    1 0

    1 0 1

    0 1 0 1 */

class Output2{

      public static void main(String args[]){

           for(int i=1;i<=4;i++){

              for(int j=1;j<=i;j++){

                            System.out.print(((i+j)%2)+" ");

                    }

                    System.out.print("\n");

                 }

     }

}       


Program 25

/* Display Triangle as follow

    1

    2 4

    3 6 9

    4 8 12 16 ... N (indicates no. of Rows) */

class Output3{

      public static void main(String args[]){

          int n = Integer.parseInt(args[0]);

                   for(int i=1;i<=n;i++){

                     for(int j=1;j<=i;j++){

                        System.out.print((i*j)+" ");

                    }

                    System.out.print("\n");

                 }

     }

}