Count all elements in an array, or something in an object (original) (raw)

(PHP 4, PHP 5, PHP 7)

count — Count all elements in an array, or something in an object

Description

count ( mixed $array_or_countable [, int $mode = COUNT_NORMAL ] ) : int

For objects, if you haveSPL installed, you can hook intocount() by implementing interfaceCountable. The interface has exactly one method,Countable::count(), which returns the return value for thecount() function.

Please see the Array section of the manual for a detailed explanation of how arrays are implemented and used in PHP.

Parameters

array_or_countable

An 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.

Caution

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.

Return Values

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.

Examples

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?> `

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