(PHP 4, PHP 5, PHP 7, PHP 8)
array_unshift — Prepend one or more elements to the beginning of an array
array_unshift() prepends passed elements to the front
of the array
. Note that the list of elements is
prepended as a whole, so that the prepended elements stay in the same
order. All numerical array keys will be modified to start counting from
zero while literal keys won't be changed.
Note:
Resets array's internal pointer to the first element.
array
The input array.
values
The values to prepend.
Returns the new number of elements in the array
.
Version | Description |
---|---|
7.3.0 | This function can now be called with only one parameter. Formerly, at least two parameters have been required. |
Example #1 array_unshift() example
<?php$queue = [ "orange", "banana"];array_unshift($queue, "apple", "raspberry");var_dump($queue);?>
The above example will output:
array(4) { [0] => string(5) "apple" [1] => string(9) "raspberry" [2] => string(6) "orange" [3] => string(6) "banana" }
Example #2 Usage with associative arrays
If one associative array is prepended to another associative array, the prepended array is numerically indexed into the former array.
<?php$foods = [ 'apples' => [ 'McIntosh' => 'red', 'Granny Smith' => 'green', ], 'oranges' => [ 'Navel' => 'orange', 'Valencia' => 'orange', ],];$vegetables = [ 'lettuce' => [ 'Iceberg' => 'green', 'Butterhead' => 'green', ], 'carrots' => [ 'Deep Purple Hybrid' => 'purple', 'Imperator' => 'orange', ], 'cucumber' => [ 'Kirby' => 'green', 'Gherkin' => 'green', ],];array_unshift($foods, $vegetables);var_dump($foods);
The above example will output:
array(3) { [0] => array(3) { 'lettuce' => array(2) { 'Iceberg' => string(5) "green" 'Butterhead' => string(5) "green" } 'carrots' => array(2) { 'Deep Purple Hybrid' => string(6) "purple" 'Imperator' => string(6) "orange" } 'cucumber' => array(2) { 'Kirby' => string(5) "green" 'Gherkin' => string(5) "green" } } 'apples' => array(2) { 'McIntosh' => string(3) "red" 'Granny Smith' => string(5) "green" } 'oranges' => array(2) { 'Navel' => string(6) "orange" 'Valencia' => string(6) "orange" } }