The **`array_key_last`** can be used to get the last key of the array.

# Syntax 

```
array_key_last(array $array): int|string|null
```
If the passed array doesn't have any element, then it returns `null`.

# Example

<?php
$arr = [
            'ONE' => 1, 
            'TWO' => 2, 
            'THREE' => 3
          ];

$lastKey = array_key_last($arr);

echo "The last key of the array is :". $lastKey;

?>

In the code above, We have created an array and get the last key of the array using the `array_key_last` method.

# Example 2 

Let's call `array_key_last` on an empty array:

<?php

  $arr = [];
  $lastKey = array_key_last($arr);

  var_dump($lastKey);

?>

In the code above, we will get `NULL` as a result because the passed array is empty.

What is the array_key_last method in PHP?

The array_key_last method in PHP returns the last key of an array or null if the array is empty.