Java program to remove duplicate elements from an array

Program to remove duplicate elements in java

import java.util.Scanner;

public class RemoveDuplicateElementFromArray {
  public static void main(String[] args) {
    /* Array instantiation */
    int[] arr_elements = new int[20];

    /* initial_element variable initialize by 0 and 
    point to the first element of the array */
    /* next_element points to next element of array */
    int initial_element, next_element;
    int i;

    /*Create Scanner Object */
    Scanner sc = new Scanner(System.in);

    /*Display array size for user*/
    System.out.print("Enter array size: ");
    int arr_size = sc.nextInt();

    /*Display message for array element*/
    System.out.println("Read Array Elements From User :");

    /*Loop to take input array elements*/
    for (i = 0; i < arr_size; ++i) {
      System.out.print("Enter array elements of index " + i + ": ");
      arr_elements[i] = sc.nextInt();
    }

    /* Display array before removing duplicate element */
    System.out.println("Before removing duplicate element array are :");

    /* Loop for displaying array elements */
    for (i = 0; i < arr_size; ++i) {
      System.out.println(arr_elements[i]);
    }

    /* Get new line
    System.out.println();
    /* Display array after removing duplicate array element */
    System.out.println("After removing duplicate element array are :");
    for (initial_element = 0; initial_element < arr_size; ++initial_element) {
      for (next_element = initial_element + 1; next_element < arr_size;) {
        /* if initial_element matches to next_element 
        then take next _element and matches till end */
        if (arr_elements[initial_element] == arr_elements[next_element]) {
          for (int temp = next_element; temp < arr_size; ++temp) {
            arr_elements[temp] = arr_elements[temp + 1];
          }
          arr_size = arr_size - 1;
        } else
          next_element++;
      }
    }

    /* Loop to display array after removing duplicate element */
    for (i = 0; i < arr_size; ++i)
      System.out.println(arr_elements[i]);
  }
}

Output

Enter array size: 7

Read Array Elements From User :
Enter array elements of index 0: 1
Enter array elements of index 1: 2
Enter array elements of index 2: 3
Enter array elements of index 3: 1
Enter array elements of index 4: 2
Enter array elements of index 5: 3
Enter array elements of index 6: 4

Before removing duplicate element array are :
1
2
3
1
2
3
4

After removing duplicate element array are :
1
2
3
4