PHP array_key_first() Function

The array_key_first() is an inbuilt function of PHP and is used to gets the first key of an array. 
You can get the first key from given array without affecting the internal array pointer.

Syntax:

array_key_first(array)

Parameters:

array: An array.

Returns the first key of array if the array is not empty; NULL otherwise.

Simple Example:

<?php

$array = ['apple' => 1, 'banana' => 2, 'mango' => 3];

$first= array_key_first($array);

var_dump($first);

?>

Output:

string(5) "apple"