PHP 8.1.31 Released!

    iterator_count

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

    iterator_count — Count the elements in an iterator

    Опис

    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.

    Параметри

    iterator

    The iterator being counted.

    Значення, що повертаються

    The number of elements in iterator.

    Журнал змін

    Версія Опис
    8.2.0 The type of iterator has been widened from Traversable to Traversable|array.

    Приклади

    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)

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    User Contributed Notes 2 notes

    up
    3
    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)

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