iterator_count

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

iterator_countCount the elements in an iterator

Description

iterator_count(Traversable|array $iterator): int

Count the elements in an iterator. iterator_count() is not guaranteed to retain the current position of the iterator.

Parameters

iterator

The iterator being counted.

Return Values

The number of elements in iterator.

Changelog

Version Description
8.2.0 The type of iterator has been widened from Traversable to Traversable|array.

Examples

Example #1 iterator_count() example

<?php
$iterator 
= new ArrayIterator(array('recipe'=>'pancakes''egg''milk''flour'));
var_dump(iterator_count($iterator));
?>

The above example will output:

int(4)

Example #2 iterator_count() modifies position

<?php
$iterator 
= new ArrayIterator(['one''two''three']);
var_dump($iterator->current());
var_dump(iterator_count($iterator));
var_dump($iterator->current());
?>

The above example will output:

string(3) "one"
int(3)
NULL

Example #3 iterator_count() in foreach loops

<?php
$iterator 
= new ArrayIterator(['one''two''three']);
foreach (
$iterator as $key => $value) {
    echo 
"$key$value ("iterator_count($iterator), ")\n";
}
?>

The above example will output:

0: one (3)

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User Contributed Notes 2 notes

up
2
fractile81 at gmail dot com
2 years ago
After using this function, the traversable's pointer will point at the end.  Examples 2 and 3 highlight this using code.

This means that when you call iterator_count($foo)...
- Before a foreach-loop on $foo, the loop will not execute because it's already at the end.  Calling $foo->rewind() will reset the traversable to the beginning.
- Inside a foreach-loop on $foo, the loop will complete the current iteration and not repeat.  Something like $foo->seek($i) can be used to reset the pointer, where $i contains the pointer's value prior to counting.
up
0
info at ensostudio dot ru
2 years ago
Safe using:
<?php
$cnt
= iterator_count(clone $iterator);
?>
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