Safe using:
<?php
$cnt = iterator_count(clone $iterator);
?>
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
iterator_count — Count the elements in an iterator
Count the elements in an iterator.
iterator_count() is not guaranteed to retain the current
position of the iterator.
iteratorThe iterator being counted.
The number of elements in iterator.
| Версія | Опис |
|---|---|
| 8.2.0 |
The type of iterator has been widened from
Traversable to
Traversable|array.
|
Приклад #1 iterator_count() example
<?php
$iterator = new ArrayIterator(array('recipe'=>'pancakes', 'egg', 'milk', 'flour'));
var_dump(iterator_count($iterator));
?>Поданий вище приклад виведе:
int(4)
Приклад #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());
?>Поданий вище приклад виведе:
string(3) "one" int(3) NULL
Приклад #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";
}?>Поданий вище приклад виведе:
0: one (3)
Be aware that counting over NoRewindIterator will make items unavailable:
<?php
$iterator = new ArrayIterator(['recipe'=>'pancakes', 'egg', 'milk', 'flour']);
$iterator = new NoRewindIterator($iterator);
var_dump($iterator->current());
var_dump(iterator_count($iterator));
var_dump($iterator->current());
$iterator->rewind(); // Does not work because it's NoRewindIterator
var_dump($iterator->current());
var_dump(iterator_count($iterator));
?>
Output:
<?php
/*
string(8) "pancakes"
int(4)
NULL
NULL
*/
int(0)
?>