PHP array_key_first() Function
Quick summary: The PHP array_key_first() function returns the first key of an array without modifying the internal pointer.
PHP array_key_first() Syntax
array_key_first(array $array): string|int|nullPHP
PHP array_key_first() Basic examples
$array = ['x'=>1,'y'=>2];
echo array_key_first($array);PHP
Output:
xReturns the first key.
PHP array_key_first() Real-world usage
$queue = ['task1'=>true,'task2'=>false];
$first = array_key_first($queue);
echo $first;PHP
Output:
task1Retrieve the first key without resetting the pointer.
PHP array_key_first() Edge cases
$empty = [];
var_dump(array_key_first($empty));PHP
Output:
NULLReturns null for empty arrays.
PHP array_key_first() Common mistakes
Using reset() unnecessarily
array_key_first() does not affect the internal pointer.
Incorrect
reset($array);
$key = key($array);Correct
$key = array_key_first($array);Use array_key_first() for cleaner access.
PHP array_key_first() Frequently Asked Questions
What does array_key_first() do?
Returns the first key of an array.
Use case?
Access first element.
Return value?
Key or null.
Introduced in PHP?
PHP 7.3.
Common mistake?
Using reset().
Performance?
Fast.
Safe?
Yes.
Handles empty array?
Returns null.
Alternative?
array_keys()[0].
Modifies array?
No.
Best practice?
Use built-in function.
Used in loops?
Yes.