iterator_count

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

    iterator_count — Count 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
    3
    oleksii dot bulba at gmail dot com
    2 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)

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