How to Replace an Element Inside Array in PHP ?

Given an array containing some elements, the task is to replace an element inside the array in PHP. There are various methods to manipulate arrays, including replacing elements.

Examples:

Input: arr = [10, 20, 30, 40, 50], index_1 = 100
Output: [10, 100, 30, 40, 50]

Input: arr = ['GFG', 'Geeks', 'Hello'], index_2 = 'Welcome'
Output: ['GFG', 'Geeks', 'Welcome']

Approach 1: Using Index Assignment

The most straightforward way to replace an element in a PHP array is to directly assign a new value to the desired index.

PHP

<?php

$arr = array(10, 30, 40, 50, 70);

$arr[1] = 100;

// Display the updated array
print_r($arr);

?>

Output

Array
(
    [0] => 10
    [1] => 100
    [2] => 40
    [3] => 50
    [4] => 70
)

Approach 2: Using array_replace() Function

PHP provides the array_replace() function that merges the values of two or more arrays. It is particularly useful for replacing specific elements.

PHP

<?php

$arr = array(10, 30, 40, 50, 70);

$modifiedArr = array_replace($arr, [1 => 100]);

// Display the modified array
print_r($modifiedArr);

?>

Output

Array
(
    [0] => 10
    [1] => 100
    [2] => 40
    [3] => 50
    [4] => 70
)

Approach 3: Using array_splice() Function

The array_splice() function allows us to remove a portion of the array and replace it with new elements.

PHP

<?php

$arr = array(10, 30, 40, 50, 70);

array_splice($arr, 1, 1, 100);

// Display the modified array
print_r($arr);

?>

Output

Array
(
    [0] => 10
    [1] => 100
    [2] => 40
    [3] => 50
    [4] => 70
)