count
(PHP 4, PHP 5)
count — Count all elements in an array, or something in an object
Description
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.
Parameters
-
var -
The array or the object.
-
mode -
If the optional
modeparameter is set toCOUNT_RECURSIVE(or 1), count() will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array.Cautioncount() can detect recursion to avoid an infinite loop, but will emit an
E_WARNINGevery time it does (in case the array contains itself more than once) and return a count higher than may be expected.
Return Values
Returns the number of elements in var.
If var is not an array or an object with
implemented Countable interface,
1 will be returned.
There is one exception, if var is NULL,
0 will be returned.
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.
Changelog
| Version | Description |
|---|---|
| 4.2.0 |
The optional mode parameter was added.
|
Examples
Example #1 count() example
<?php
$a[0] = 1;
$a[1] = 3;
$a[2] = 5;
$result = count($a);
// $result == 3
$b[0] = 7;
$b[5] = 9;
$b[10] = 11;
$result = count($b);
// $result == 3
$result = count(null);
// $result == 0
$result = count(false);
// $result == 1
?>
Example #2 Recursive count() example
<?php
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard', 'pea'));
// recursive count
echo count($food, COUNT_RECURSIVE); // output 8
// normal count
echo count($food); // output 2
?>
See Also
- is_array() - Finds whether a variable is an array
- isset() - Determine if a variable is set and is not NULL
- strlen() - Get string length
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