# Replace every element of the array by its next element

• Last Updated : 05 Aug, 2021

Given an array arr, the task is to replace each element of the array with the element that appears after it and replace the last element with -1.
Examples:

Input: arr[] = {5, 1, 3, 2, 4}
Output: 1 3 2 4 -1
Input: arr[] = {6, 8, 32, 12, 14, 10, 25 }
Output: 8 32 12 14 10 25 -1

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Approach: Traverse the array from 0 to n-2 and update arr[i] = arr[i+1]. In the end set a[n-1] = -1 and print the contents of the updated array.
Below is the implementation of the above approach:

## C++

 `// C++ program to replace every element of the array``// with the element that appears after it``#include ``using` `namespace` `std;` `// Function to print the array after replacing every element``// of the array with the element that appears after it``void` `updateArray(``int` `arr[], ``int` `n)``{``    ``// Update array``    ``for` `(``int` `i = 0; i <= n - 2; i++)``        ``arr[i] = arr[i + 1];` `    ``// Change the last element to -1``    ``arr[n - 1] = -1;` `    ``// Print the updated array``    ``for` `(``int` `i = 0; i < n; i++)``        ``cout << arr[i] << ``" "``;``}` `// Driver program``int` `main()``{``    ``int` `arr[] = { 5, 1, 3, 2, 4 };``    ``int` `N = ``sizeof``(arr) / ``sizeof``(arr);``    ``updateArray(arr, N);``    ``return` `0;``}`

## Java

 `// Java program to replace every element``// of the array with the element that``// appears after it``class` `GFG``{` `// Function to print the array after``// replacing every element of the array``// with the element that appears after it``static` `void` `updateArray(``int` `arr[], ``int` `n)``{``    ``// Update array``    ``for` `(``int` `i = ``0``; i <= n - ``2``; i++)``        ``arr[i] = arr[i + ``1``];` `    ``// Change the last element to -1``    ``arr[n - ``1``] = -``1``;` `    ``// Print the updated array``    ``for` `(``int` `i = ``0``; i < n; i++)``        ``System.out.print(arr[i] + ``" "``);``}` `// Driver Code``public` `static` `void` `main(String []args)``{``    ``int` `arr[] = { ``5``, ``1``, ``3``, ``2``, ``4` `} ;``    ``int` `N = arr.length ;``    ``updateArray(arr, N);``}``}` `// This code is contributed by Ryuga`

## Python3

 `# Python3 program to replace every``# element of the array with the``# element that appears after it` `# Function to print the array after``# replacing every element of the``# array with the element that appears``# after it``def` `updateArray(arr, n):` `    ``# Update array``    ``for` `i ``in` `range` `(n ``-` `1``):``        ``arr[i] ``=` `arr[i ``+` `1``]` `    ``# Change the last element to -1``    ``arr[n ``-` `1``] ``=` `-``1` `    ``# Print the updated array``    ``for` `i ``in` `range``( n):``        ``print` `(arr[i], end ``=` `" "``)` `# Driver Code``if` `__name__ ``=``=` `"__main__"``:` `    ``arr ``=` `[ ``5``, ``1``, ``3``, ``2``, ``4` `]``    ``N ``=` `len``(arr)``    ``updateArray(arr, N)` `# This code is contributed``# by ChitraNayal`

## C#

 `// C# program to replace every element``// of the array with the element that``// appears after it``using` `System;` `class` `GFG``{` `// Function to print the array after``// replacing every element of the array``// with the element that appears after it``static` `void` `updateArray(``int``[] arr, ``int` `n)``{``    ``// Update array``    ``for` `(``int` `i = 0; i <= n - 2; i++)``        ``arr[i] = arr[i + 1];` `    ``// Change the last element to -1``    ``arr[n - 1] = -1;` `    ``// Print the updated array``    ``for` `(``int` `i = 0; i < n; i++)``        ``Console.Write(arr[i] + ``" "``);``}` `// Driver Code``public` `static` `void` `Main()``{``    ``int``[] arr = { 5, 1, 3, 2, 4 } ;``    ``int` `N = arr.Length ;``    ``updateArray(arr, N);``}``}` `// This code is contributed``// by Akanksha Rai`

## PHP

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## Javascript

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Output:
`1 3 2 4 -1`

Time Complexity : O(n)
Auxiliary Space: O(1)

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