iterator_count

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

    iterator_count — Count the elements in an iterator

    Beschreibung

    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.

    Parameter-Liste

    iterator

    The iterator being counted.

    Rückgabewerte

    The number of elements in iterator.

    Changelog

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

    Beispiele

    Beispiel #1 iterator_count() example

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

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

    int(4)

    Beispiel #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());
    ?>

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

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

    Beispiel #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";
    }    ?>

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

    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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