iterator_count

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

    iterator_count — Count the elements in an iterator

    Descrizione

    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.

    Elenco dei parametri

    iterator

    The iterator being counted.

    Valori restituiti

    The number of elements in iterator.

    Log delle modifiche

    Versione Descrizione
    8.2.0 The type of iterator has been widened from Traversable to Traversable|array.

    Esempi

    Example #1 iterator_count() example

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

    Il precedente esempio visualizzerà:

    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());
    ?>

    Il precedente esempio visualizzerà:

    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";
    }    ?>

    Il precedente esempio visualizzerà:

    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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