array_key_last(): to get the last key of an array

key = array_key_last ($input_array);

Example 1

$input=array(1,2,3,4,5);
echo array_key_last($input);

4

Example 2

$input=array('One' =>'First','Two'=>'Second','Three'=>'Third','Fourth');
echo var_dump(array_key_last($input));

int(0)

Example 3: Using array_key_last() with Numeric Array

<?php
$input = array(10, 20, 30, 40);
echo array_key_last($input);  // Output: 3
?>

Example 4: Using array_key_last() with Associative Array

<?php
$input = array('a' => 'Apple', 'b' => 'Banana', 'c' => 'Cherry');
echo array_key_last($input);  // Output: 'c'
?>

Example 5: Handling an Empty Array

<?php
$emptyArray = array();
echo array_key_last($emptyArray);  // Output: NULL
?>

Example 6: Using array_key_last() After Array Modifications

<?php
$input = array('first' => 100, 'second' => 200, 'third' => 300);
unset($input['third']);
echo array_key_last($input);  // Output: 'second'
?>