array_key_exists(3) [php man page]

ARRAY_KEY_EXISTS(3)							 1						       ARRAY_KEY_EXISTS(3)

array_key_exists - Checks if the given key or index exists in the array

SYNOPSIS

       bool array_key_exists (mixed  $key, array  $array)

DESCRIPTION

       array_key_exists(3) returns TRUE if the given $key is set in the array. $key can be any value possible for an array index.

PARAMETERS

	      o $key
		- Value to check.

	      o $array
		- An array with keys to check.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

EXAMPLES

       Example #1

	      array_key_exists(3) example

	      <?php
	      $search_array = array('first' => 1, 'second' => 4);
	      if (array_key_exists('first', $search_array)) {
		  echo "The 'first' element is in the array";
	      }
	      ?>

       Example #2

	      array_key_exists(3) vs isset(3)

	      isset(3) does not return TRUE for array keys that correspond to a NULL value, while array_key_exists(3) does.

	      <?php
	      $search_array = array('first' => null, 'second' => 4);

	      // returns false
	      isset($search_array['first']);

	      // returns true
	      array_key_exists('first', $search_array);
	      ?>

NOTES

       Note

	       For backward compatibility, the following deprecated alias may be used: key_exists(3)

       Note

	       For  backward compatibility reasons, array_key_exists(3) will also return TRUE if $key is a property defined within an object given
	      as $array. This behaviour should not be relied upon, and care should be taken to ensure that $array is an array.

	       To check whether a property exists in an object, use property_exists(3).

SEE ALSO

       isset(3), array_keys(3), in_array(3), property_exists(3).

PHP Documentation Group 												       ARRAY_KEY_EXISTS(3)

ARRAY_SEARCH(3) 							 1							   ARRAY_SEARCH(3)

array_search - Searches the array for a given value and returns the corresponding key if successful

SYNOPSIS

       mixed array_search (mixed  $needle, array  $haystack, [bool  $strict = false])

DESCRIPTION

	Searches $haystack for $needle.

PARAMETERS

	      o $needle
		- The searched value.

	      Note

		      If $needle is a string, the comparison is done in a case-sensitive manner.

	      o $haystack
		- The array.

	      o $strict
		-  If  the  third  parameter  $strict  is  set to TRUE then the array_search(3) function will search for identical elements in the
		$haystack. This means it will also check the types of the $needle in the $haystack, and objects must be the same instance.

RETURN VALUES

	Returns the key for $needle if it is found in the array, FALSE otherwise.

	If $needle is found in $haystack more than once, the first matching key is returned. To return the  keys  for  all  matching  values,  use
       array_keys(3) with the optional $search_value parameter instead.

       Warning

	      This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on
	      Booleans for more information. Use the === operator for testing the return value of this function.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.0	|						    |
       |	|						    |
       |	|  As with all internal PHP functions as of  5.3.0, |
       |	| array_search(3)  returns  NULL if invalid parame- |
       |	| ters are passed to it.			    |
       |	|						    |
       | 4.2.0	|						    |
       |	|						    |
       |	|  Prior to PHP 4.2.0, array_search(3) returns NULL |
       |	| on failure instead of FALSE.			    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      array_search(3) example

	      <?php
	      $array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');

	      $key = array_search('green', $array); // $key = 2;
	      $key = array_search('red', $array);   // $key = 1;
	      ?>

SEE ALSO

       array_keys(3), array_values(3), array_key_exists(3), in_array(3).

PHP Documentation Group 													   ARRAY_SEARCH(3)