Count all elements in an array, or something in an object
(PHP 4, PHP 5)
count — Count all elements in an array, or something in an object
Descriptionint count ( mixed
$mode= COUNT_NORMAL ] )
Counts all elements in an array, or something in an object.
For objects, if you have SPL installed, you can hook into count() by implementing interface Countable. The interface has exactly one method, Countable::count(), which returns the return value for the count() function.
Please see the Array section of the manual for a detailed explanation of how arrays are implemented and used in PHP.
The array or the object.
If the optional
modeparameter is set to
COUNT_RECURSIVE(or 1), count() will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array. count() does not detect infinite recursion.
Returns the number of elements in
varis not an array or an object with implemented Countable interface, 1 will be returned. There is one exception, if
NULL, 0 will be returned.Caution
count() may return 0 for a variable that isn't set, but it may also return 0 for a variable that has been initialized with an empty array. Use isset() to test if a variable is set.
Version Description 4.2.0 The optional
modeparameter was added.
Example #1 count() example
$a = 1;
$a = 3;
$a = 5;
$result = count($a);
// $result == 3
$b = 7;
$b = 9;
$b = 11;
$result = count($b);
// $result == 3
$result = count(null);
// $result == 0
$result = count(false);
// $result == 1
Example #2 Recursive count() example
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard', 'pea'));
// recursive count
echo count($food, COUNT_RECURSIVE); // output 8
// normal count
echo count($food); // output 2