PHP array_unshift() Function
Topic: PHP Array ReferencePrev|Next
Description
The array_unshift() function inserts one or more elements at the beginning of an array.
All numerical array keys will be modified to start counting from zero. String keys will remain the same.
The following table summarizes the technical details of this function.
| Return Value: | Returns the new number of elements in the array. |
|---|---|
| Changelog: | Since PHP 7.3.0 this function can now be called with only one parameter (i.e. array). Previously, at least two parameters have been required. |
| Version: | PHP 4+ |
Syntax
The basic syntax of the array_unshift() function is given with:
array_unshift(array, value1, value2, ...);
The following example shows the array_unshift() function in action.
Example
Run this code »<?php
// Sample array
$colors = array("red", "green", "blue");
// Prepending two values to the colors array
array_unshift($colors, "yellow", "orange");
print_r($colors);
?>Parameters
The array_unshift() function accepts the following parameters.
| Parameter | Description |
|---|---|
| array | Required. Specifies the array to work on. |
| value1, value2, ... | Optional. Specifies the values to prepend to the beginning of the array. |
More Examples
Here're some more examples showing how array_unshift() function actually works:
You can also prepend values to the associative arrays as demonstrated below:
Example
Run this code »<?php
// Sample array
$alphabets = array("a"=>"apple", "b"=>"ball", "c"=>"cat", "d"=>"dog");
// Prepending a single value to the alphabets array
array_unshift($alphabets, "elephant");
print_r($alphabets);
?>
