How to remove duplicate elements of an array in java?

Java 8 Object Oriented Programming Programming

To detect the duplicate values in an array you need to compare each element of the array to all the remaining elements in case of a match you got your duplicate element.

One solution to do so you need to use two loops (nested) where the inner loop starts with i+1 (where i is the variable of the outer loop) to avoid repetitions.

Apache Commons provides a library named org.apache.commons.lang3 and, following is the maven dependency to add a library to your project.

<dependencies>
   <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
      <version>3.0</version>
   </dependency>
</dependencies>

This package provides a class named ArrayUtils using the remove() method of this class you can delete the detected duplicate elements of the given array.

Example

import java.util.Arrays;
import java.util.Scanner;
import org.apache.commons.lang3.ArrayUtils;
public class DeleteDuplicate {
   public static void main(String args[]) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter the size of the array that is to be created::");
      int size = sc.nextInt();
      int[] myArray = new int[size];
      System.out.println("Enter the elements of the array ::");
      for(int i=0; i<size; i++) {
         myArray[i] = sc.nextInt();
      }
      System.out.println("The array created is ::"+Arrays.toString(myArray));
      for(int i=0; i<myArray.length-1; i++) {
         for (int j=i+1; j<myArray.length; j++) {
            if(myArray[i] == myArray[j]) {
               myArray = ArrayUtils.remove(myArray, j);
            }
         }
      }
      System.out.println("Array after removing elements ::"+Arrays.toString(myArray));
   }
}

Output

Enter the size of the array that is to be created ::
6
Enter the elements of the array ::
232
232
65
47
89
42
The array created is :: [232, 232, 65, 47, 89, 42]
Array after removing elements :: [232, 65, 47, 89, 42]

Monica Mona

Published on 09-Jan-2018 05:36:12

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