How to split all keys from a PHP array?

In this tutorial, you will learn how to split all the keys of a PHP array into a new array.

PHP array_keys() Function

With the help of the PHP array_keys() function, you can split all the keys of an array into a new array.

This function takes three parameters and returns a new array with keys.

array_keys(array, value, strict)

• array (Required) – The array whose keys you want to split.
• value (Optional) – This is an optional parameter, this parameter takes any value of an array whose key you want to get.
• strict (Optional) – It is also optional, and by default it is FALSE. If you want to get the key of an exact type of value, then pass TRUE.

<?php
$user = ["name" => "John Doe", "age" => "24", "email" => "jhon1[email protected]"];

$keys = array_keys($user);

print_r($keys);

Array
(
    [0] => name 
    [1] => age  
    [2] => email
)

Example with the value parameter of the array_keys

<?php
$user = ["name" => "John Doe", "age" => "24", "email" => "[email protected]"];

$keys = array_keys($user, "24");

print_r($keys);

Array
(
    [0] => age
)

Example with the strict parameter of the array_keys

<?php
$num = [8, 5, 45, "5", 7, "2"];

$key = array_keys($num, 5);

$key_strict = array_keys($num, "5", true);

print_r($key);
print_r($key_strict);

Array       
(
    [0] => 1
    [1] => 3
)
Array       
(
    [0] => 3
)