Insert an item at a specific position in an array in PHP

This post will discuss how to insert an item at a specific position in an array in PHP.

1. Using `array_slice()` function

A simple solution to insert an item at a specific position in an array is using the array_slice() function. The idea is to extract a slice of the array using array_slice() function and then recombine the parts using the array_merge() function.

The following code demonstrates this:

<?php

$arr = [1, 2, 3, 5];

$pos = 3;

$val = 4;

$result = array_merge(array_slice($arr, 0, $pos), array($val), array_slice($arr, $pos));

print_r($result);

/* Output:

Array

(

[0] => 1

[1] => 2

[2] => 3

[3] => 4

[4] => 5

)

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For associative arrays,

<?php

$array = array(

'b' => 'blue',

'r' => 'red',

'g' => 'green'

);

$pos = 3;

$val = array('y' => 'yellow');

$result = array_merge(array_slice($array, 0, $pos), $val, array_slice($array, $pos));

print_r($result);

/* Output:

Array

(

[b] => blue

[r] => red

[g] => green

[y] => yellow

)

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For associative arrays, we can also use the union operator (+) to recombine the parts, which appends the right-hand array to the left-hand array.

<?php

$array = array(

'b' => 'blue',

'r' => 'red',

'g' => 'green'

);

$pos = 1;

$val = array('y' => 'yellow');

$result = array_slice($array, 0, $pos) + $val + array_slice($array, $pos);

print_r($result);

/* Output:

Array

(

[b] => blue

[y] => yellow

[r] => red

[g] => green

)

Download Run Code

Note that for a normal array where the keys are integer, + operator might not work as expected.

2. Using `array_splice()` function

Another solution is to use array_splice() function, which removes a portion of the array and replace it with the elements of the specified array.

<?php

$arr = [1, 2, 3, 5];

$pos = 3;

$val = 4;

array_splice($arr, $pos, 0, $val);

print_r($arr);

/* Output:

Array

(

[0] => 1

[1] => 2

[2] => 3

[3] => 4

[4] => 5

)

Download Run Code

Note that array_splice() does not preserve numeric keys. Consider the following example, which is trying to splice an associative array with numeric keys using array_splice() function.

<?php

$arr = array(

0 => 'blue',

1 => 'red',

2 => 'green'

);

$pos = 1;

$val = 'yellow';

array_splice($arr, $pos, 0, $val);

print_r($arr);

/* Output:

Array

(

[0] => blue

[1] => red

[2] => green

[3] => yellow

)

Download Run Code

That’s all about inserting an item at a specific position in an array in PHP.

Insert an item at a specific position in an array in PHP

1. Using array_slice() function

2. Using array_splice() function

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1. Using `array_slice()` function

2. Using `array_splice()` function