Reverse elements of an array

Write a program to input elements in an array and find reverse of an array. So in this post, we are going to learn, how to find reverse of an array in C programming, Python, Java and JavaScript and logic to find reverse of an array in C program.

reverse elements of an array

Example -

Input: 1, 2, 3, 4, 5
Output: 5, 4, 3, 2, 1

Input: 3, 2, 5, 9, 7, 8
Output: 8, 7, 9, 5, 2, 3

Iterative solution:

Take input values into an array
Loop through the array from index=0 to size/2 and swap arr[index] from arr[size-1-index]
Then, print the array

Python

num = int(input('Enter number of array elements: '))
arr = []
print('Enter array elements -')
for _ in range(num):
    arr.append(int(input()))

for i in range(len(arr) // 2):
    arr[i], arr[len(arr)-i-1] = arr[len(arr)-i-1], arr[i]

print('After reversing -')
print(arr)

Java

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);

      System.out.print("Enter number of elements: ");
      int num = sc.nextInt();

      int[] arr = new int[num];

      System.out.println("Enter array elements -");

      for (int i = 0; i < num; i++)
          arr[i] = sc.nextInt();

      for (int i = 0; i < arr.length / 2; i++) {
          int temp;
          temp = arr[i];
          arr[i] = arr[arr.length - 1 - i];
          arr[arr.length - 1 - i] = temp;
      }

      System.out.println("After reversing -");
      for (int i = 0; i < num; i++) {
          System.out.println(arr[i]);
      }
  }
}

#include <stdio.h>
    
void main(void) {
    int arr[5], n=5, i, temp;

    printf("Enter array elements\n");
    for (i = 0; i < n; i++)
        scanf("%d", &arr[i]);

    for (i = 0; i < n / 2; i++)
    {
        temp = arr[i];
        arr[i] = arr[n-i-1];
        arr[n-i-1] = temp;
    }

    printf("\nAfter reversing\n");
    for (i = 0; i < n; i++)
        printf("%d\n", arr[i]);
}

JavaScript

arr = [1, 2, 3, 4, 5];
    
for (let i = 0; i < arr.length/2; i++) {
    // Destructuring Assignment Array
    [arr[i], arr[arr.length-i-1]] = [arr[arr.length-i-1], arr[i]]
}

console.log(arr);

Output

Enter number of array elements: 5
Enter array elements -
1
2
3
4
5
After reversing -
[5, 4, 3, 2, 1]