PHP array_is_list() Function
Quick summary: The PHP array_is_list() function checks whether an array has sequential integer keys starting from 0 without gaps.
PHP array_is_list() Syntax
array_is_list(array $array): boolPHP
PHP array_is_list() Basic examples
$array = [10,20,30];
var_dump(array_is_list($array));PHP
Output:
bool(true)Sequential numeric keys starting from 0.
$array = [1=>10,2=>20];
var_dump(array_is_list($array));PHP
Output:
bool(false)Keys must start at 0 and be consecutive.
PHP array_is_list() Real-world usage
PHP array_is_list() Edge cases
$empty = [];
var_dump(array_is_list($empty));PHP
Output:
bool(true)An empty array is considered a list.
PHP array_is_list() Common mistakes
Assuming numeric keys always mean list
Keys must be 0-based and consecutive.
Incorrect
array_is_list([1=>'a',2=>'b']);Correct
array_is_list(['a','b']);Ensure keys start at 0 with no gaps.
PHP array_is_list() Frequently Asked Questions
What does array_is_list() do?
Checks if an array is a list with sequential numeric keys.
Use case?
Validate array structure.
Return type?
bool.
Introduced in PHP?
PHP 8.1.
Common mistake?
Assuming associative arrays.
Handles empty array?
Yes.
Strict?
Yes.
Performance?
Fast.
Alternative?
Manual checks.
Safe?
Yes.
Used in JSON?
Yes.
Best practice?
Use for validation.