What is PHP list() Function?
If you want to assign values of an array to a list of variables in a single statement, use PHP list() function.
Syntax:
list(variable1, variable2, variable3,… variableN);
Parameters:
The Function has 1 required parameter and one or more optional parameter-
Variable1 (Required): It is the first variable.
variable2, variable3,… variableN (Optional): These are one or more variables.
Return Values:
The function returns the original array. Check example 2.
Examples:
Example 1:
<?php
$language = ["HTML", "CSS", "JavaScript" , "PHP"];
list($a, $b, $c, $d) = $language;
echo "Markup language: " .$a . "<br>";
echo "Style sheet language: " .$b . "<br>";
echo "Scripting language: " .$c . "<br>";
?>
Output:
Markup language: HTML
Style sheet language: CSS
Scripting language: JavaScript
Explanation:
CODE GOES HERE………
Example 2:
<pre>
<?php
$language = ["HTML", "CSS", "JavaScript" , "PHP"];
$returned_value = list($a, $b, $c, $d) = $language;
print_r($returned_value);
?>
</pre>
Output:
Array
(
[0] => HTML
[1] => CSS
[2] => JavaScript
[3] => PHP
)
Example 3:
<?php
$language1 = ["HTML", "CSS", "JavaScript"];
list($a, $b, $c, $d) = $language1;
echo "Markup language: " .$a . "<br>";
echo "Style sheet language: " .$b . "<br>";
echo "Scripting language: " .$c . "<br>";
echo "Server side language: " .$d . "<br>";
?>
Output:
Warning: Undefined array key 3 in D:\xampp\htdocs\list.php on line 3
Markup language: HTML
Style sheet language: CSS
Scripting language: JavaScript
Server side language:
Example 4:
<?php
$language = ["HTML", "CSS", "JavaScript" , "PHP"];
list($a, , , $b) = $language;
echo "Markup language: " .$a . "<br>";
echo "Server side language: " .$b . "<br>";
?>
Output:
Markup language: HTML
Server side language: PHP
Example 5:
<?php
$frontend = ["Markup" => "HTML", "Styling" => "CSS", "Scripting" => "JavaScript"];
list("Markup" => $MU, "Styling" => $STL, "Scripting" => $SCT) = $frontend;
echo "Markup language: " . $MU . "<br>";
echo "Style sheet language: " . $STL . "<br>";
echo "Scripting language: " . $SCT;
?>
Output:
Markup language: HTML
Style sheet language: CSS
Scripting language: JavaScript
Notes on list() Function:
- list() is actually a language construct not a function.
- List() is also called “array destructuring” as it extracts elements from an array to individual variables in a single statement.
- You can skip an element by just omitting it but keeping its comma. Check example 4.
Caution:
If you try to access assign more variables than the number of item exists in the array, PHP throws an E_WARNING. Check example 2.
PHP Version Support:
PHP 4, PHP 5, PHP 7, PHP 8
Summary: PHP list() Function
The list() function is a built-in PHP function and part of the PHP’s array functions. PHP list() construct is a quick and easy way to extract array elements to variables.