(PHP 4, PHP 5, PHP 7)
count — Count all elements in an array, or something in an object
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.
array_or_countableAn array or Countable object.
mode
If the optional mode parameter 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() can detect recursion to avoid an infinite
loop, but will emit an E_WARNING every time it
does (in case the array contains itself more than once) and return a
count higher than may be expected.
Returns the number of elements in array_or_countable.
When the parameter is neither an array nor an object with
implemented Countable interface,
1 will be returned.
There is one exception, if array_or_countable is NULL,
0 will be returned.
Example #1 count() example
<?php
$a[0] = 1;
$a[1] = 3;
$a[2] = 5;
var_dump(count($a));
$b[0] = 7;
$b[5] = 9;
$b[10] = 11;
var_dump(count($b));
var_dump(count(null));
var_dump(count(false));
?>
The above example will output:
int(3) int(3) Warning: count(): Parameter must be an array or an object that implements Countable in … on line 12 // as of PHP 7.2 int(0) Warning: count(): Parameter must be an array or an object that implements Countable in … on line 14 // as of PHP 7.2 int(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
?>
| Version | Description |
|---|---|
| 7.2.0 |
count() will now yield a warning on invalid countable types
passed to the array_or_countable parameter.
|