iterator_count

(PHP 5 >= 5.1.0, PHP 7)

iterator_countCount the elements in an iterator

Descrierea

iterator_count ( Traversable $iterator ) : int

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

Parametri

iterator

The iterator being counted.

Valorile întoarse

The number of elements in iterator.

Exemple

Example #1 iterator_count() example

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

Exemplul de mai sus va afișa:

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());
?>

Exemplul de mai sus va afișa:

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";
}
?>

Exemplul de mai sus va afișa:

0: one (3)

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User Contributed Notes 2 notes

up
2
info at ensostudio dot ru
4 years ago
Safe using:
<?php
$cnt
= iterator_count(clone $iterator);
?>
up
1
oleksii dot bulba at gmail dot com
3 years ago
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)

?>
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