No of Occurrence in Array

package com.tutorial4u;

import java.util.HashMap;

/************************************************************

 No of Occurrence in Array

************************************************************/

public class NoOfOccurrenceInArray {

      public static void main(String[] args) {

            int [] numbers = new int[] {10,12,13,14,12,11,10,20,21,14,22};

            int count =0;

            HashMap<Integer, Integer> map = new HashMap<>();

            for(Integer i : numbers) {

                  if(map.containsKey(i)) {

                        count = map.get(i);

                        map.put(i, count+1);

                  }else {

                        map.put(i, 1);

                  }

            }

            System.out.println(map);

      }

}

 

 Output :

{20=1, 21=1, 22=1, 10=2, 11=1, 12=2, 13=1, 14=2}

Find odd or even Numbers in an Array

package com.tutorial4u;

import java.util.Scanner;

/*Java Program to Find odd or even Numbers in an Array*/

public class EvenOrOddInArray {

     public static void main(String[] args) {

           Scanner sc = new Scanner(System.in);

           System.out.print("Enter the size of Array : ");

           int num = sc.nextInt();

           int arr[] = new int[num];

           System.out.println("Enter all the element : ");

           for(int i=0;i<num;i++){

                arr[i]=sc.nextInt();

           }

           for (int i = 0; i <num; i++) {

                if (arr[i] % 2 == 0)

                      System.out.println("even");

                else

                      System.out.println("odd");

           }

     }

}

Output:

Enter the size of Array : 5

Enter all the element :

22

21

33

42

24

even

odd

odd

even

even

Count Duplicate Character

package com.tutorial4u;

import java.util.HashSet;

import java.util.Scanner;

public class DuplicateCharCount {

     public static void main(String[] args) {

           int count = 0;

           System.out.print("Enter any String : ");

           Scanner sc = new Scanner(System.in);

           String str = sc.nextLine();

           char[] ch = str.toCharArray();

           System.out.print("Duplicate character are : ");

           for(int i = 0;i<ch.length;i++){

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

                      if((ch[i] == ch[j]) && (i!=j)){

                           System.out.print(ch[i]);

                           count++;

                           break;

                      }

                }

           }

     }

}

Output : 

Enter any String : tutorial4u

Duplicate character are : tu

Remove Duplicate String From Two String

package com.tutorial4u;

public class DeleteRepetedCharacterFromTwoString {

     public static void main(String[] args) {

           String s1 = "Tutorial";

        String s2 = "TotalJava";

        System.out.println("String s1 is = " + s1 + " , String s2 is = " + s2);

        char c1[] = s1.toCharArray();

        char c2[] = s2.toCharArray();

       

        for (int i = 0; i < c1.length; i++) {

          

               boolean charMatch = false;

              

               for (int j = 0; j < c2.length; j++) {

                     if ((String.valueOf(c1[i])).toLowerCase().equals(

                                   ((String.valueOf(c2[j])).toLowerCase()))) {

                       charMatch = true;

                            break;

                     }

               }

               if (charMatch) {

                     s1 = s1.replaceAll(String.valueOf(c1[i]).toUpperCase(), "");

                     s1 = s1.replaceAll(String.valueOf(c1[i]).toLowerCase(), "");

                     s2 = s2.replaceAll(String.valueOf(c1[i]).toLowerCase(), "");

                     s2 = s2.replaceAll(String.valueOf(c1[i]).toUpperCase(), "");

               }

        }

        System.out.println("After deleted s1 = " + s1 + ",  after deleted s2 = " + s2);

     }

}

Output :

String s1 is = Tutorial , String s2 is = TotalJava

After deleted s1 = uri,  after deleted s2 = Jv

Write a Java Program to Find Random Number

package com.tutorial4u;

import java.util.Random;

import java.util.Scanner;

public class RandomNumber {

     public static void main(String[] args)

    {

        int maxRange;

        Scanner sc = new Scanner(System.in);

        Random rand = new Random();

       

        System.out.print("Please enter maximum range: ");

        maxRange = sc.nextInt();

       

        for(int i=1; i<=10; i++)

        {

            System.out.println(rand.nextInt(maxRange));

        }

    }

}

Output:

Please enter maximum range: 500

223

263

397

375

371

468

71

124

377

374

Note : Sometimes situation arises where random numbers are required to be generated between the ranges.

package com.tutorial4u;

import java.util.Random;

import java.util.Scanner;

public class RandomNumber {

     public static void main(String[] args)

    {

           Scanner sc = new Scanner(System.in);

        System.out.print("Please enter Minimum Range : ");

        int minRange = sc.nextInt();

        System.out.print("Please enter Maximum Range : ");

        int maxRange = sc.nextInt();

        Random rand = new Random();

        int value = rand.nextInt(maxRange - minRange) + minRange;

        System.out.println(value);

    }

}

Output :

Please enter Minimum Range : 1000

Please enter Maximum Range : 5000

4304