PHP array_key_last() function

The array_key_last () function in PHP gets the last key of an array if the specified array is not empty.

Syntax

array_key_last ( array $array ) 

Parameter

array(required)- This parameter signifies the input array.

Return

This function returns the last key of the specified array if the array is not empty else it returns NULL.

Example 1

$array = ['first' => 1, 'second' => 2, 'third' => 3,'fourth' => 4];
echo("Array : \n");
var_export($array);
//will return the last key for $array
$lastKey = array_key_last($array);
//printing the returned value
echo("\nThe last key of the array is ");
var_dump($lastKey);
?> 

Output

Array : 
array (
  'first' => 1,
  'second' => 2,
  'third' => 3,
  'fourth' => 4,
)
The last key of the array is string(6) "fourth" 

Example 2

 96, 'Harshit' => 94, 'Sapna' => 93];
echo("Student Array : \n");
var_export($contestent_array);
//will return the last key for $array
$lastKey = array_key_last($contestent_array);
//printing the returned value
echo("\nThe II runner up is ");
var_dump($lastKey);
//removing the last element of the array
array_pop($contestent_array);
echo("\nThe I runner up is ");
var_dump(array_key_last($contestent_array));
//removing the last element of the array
array_pop($contestent_array);
echo("\nThe winner of the match is ");
var_dump(array_key_last($contestent_array));
?> 

Output

Student Array: 
array (
  'Reema' => 96,
  'Harshit' => 94,
  'Sapna' => 93,
)
The II runner up is string(5) "Sapna"
The I runner up is string(7) "Harshit"
The winner of the match is string(5) "Reema" 

Example 3

Output

Array: 
'The first key of the array is 0' 

Example 4

'Reema',1 => 'Harshit',2 =>'Sapna'];
echo("Student Array : \n");
var_export($array);
//will return the last key for $array
$lastKey = array_key_last($array);
//printing the returned value
echo("\nThe last element is ");
var_dump($lastKey);
//adding elements at the end of the array
array_push($array,"Amar","Sukla");
echo("\nNew Array: ");
var_export($array);
echo("\nThe last element is ".array_key_last($array));
?> 

Output

Student Array : 
array (
  0 => 'Reema',
  1 => 'Harshit',
  2 => 'Sapna',
)
The last element is int(2)
New Array: array (
  0 => 'Reema',
  1 => 'Harshit',
  2 => 'Sapna',
  3 => 'Amar',
  4 => 'Sukla',
)
The last element is 4