PHP array_unshift() Function

Insert the element "blue" to an array:

<?php
$a=array("a"=>"red","b"=>"green");
array_unshift($a,"blue");
print_r($a);
?>

Definition and Usage

The array_unshift() function inserts new elements to an array. The new array values will be inserted in the beginning of the array.

Tip: You can add one value, or as many as you like.

Note: Numeric keys will start at 0 and increase by 1. String keys will remain the same.

array_unshift(array, value1, value2, value3, ...)

Parameter	Description
array	Required. Specifying an array
value1	Optional. Specifies a value to insert (Required in PHP versions before 7.3)
value2	Optional. Specifies a value to insert
value3	Optional. Specifies a value to insert

Return Value:	Returns the new number of elements in the array
PHP Version:	4+
PHP Changelog:	PHP 7.3: This function can now be called with only the array parameter

Show the return value:

<?php
$a=array("a"=>"red","b"=>"green");
print_r(array_unshift($a,"blue"));
?>

Using numeric keys:

<?php
$a=array(0=>"red",1=>"green");
array_unshift($a,"blue");
print_r($a);
?>