Core PHP

Introduction First Program PHP Comments PHP Variables PHP $ and $$ Variables PHP Echo and Print PHP Data Types PHP Strings PHP Constants PHP Operators PHP If Else PHP Switch PHP While Loop PHP For Loop PHP For each Loop PHP Do while PHP Array PHP Associative Array PHP Multidimensional Array PHP Array Functions PHP Strings PHP Forms PHP Multiple Inheritance PHP Date & Time PHP Include & Require PHP isset PHP Implode PHP Explode PHP MySQL

CMS Tutorial

Word Press Tutorial

PHP key() Function
2019-10-13 09:03:41

PHP key() Function

PHP key() Function

The key() function in PHP fetches a key from an array and returns the index element of the current array position.

Syntax

key ( array $array )

Parameter

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

Return

This function returns the key of the array element that's currently being pointed to by the internal pointer.  It returns null If the internal pointer points beyond the end of the elements list or the array is empty.

Example 1

 'apple',2 => 'orange', 3 => 'grape', 4 => 'apple', 5 => 'mango');
 //will return the key value of the current pointer
  echo "The current pointer is at ".key($array)." key.\n";//will return 1
 ?>

Output

The current pointer is at 1 key.

Example 2

 'apple',2 => 'orange', 3 => 'grape', 4 => 'apple', 5 => 'mango');
 //will return the pointer to the end of the array
 end($array);
 //will return the key value of the current pointer
  echo "The current pointer is at ".key($array)." key.\n";//will return 5
 ?>

Output

The current pointer is at 5 key.

Example 3

Output

PHP Warning:  key() expects parameter 1 to be array, null given in /workspace/Main.php on line 5