After using this function, the traversable's pointer will point at the end. Examples 2 and 3 highlight this using code.
This means that when you call iterator_count($foo)...
- Before a foreach-loop on $foo, the loop will not execute because it's already at the end. Calling $foo->rewind() will reset the traversable to the beginning.
- Inside a foreach-loop on $foo, the loop will complete the current iteration and not repeat. Something like $foo->seek($i) can be used to reset the pointer, where $i contains the pointer's value prior to counting.
iterator_count
(PHP 5 >= 5.1.0, PHP 7)
iterator_count — Count the elements in an iterator
Opis
Count the elements in an iterator.
iterator_count() is not guaranteed to retain the current
position of the iterator.
Parametry
-
iterator -
The iterator being counted.
Zwracane wartości
The number of elements in iterator.
Przykłady
Przykład #1 iterator_count() example
<?php
$iterator = new ArrayIterator(array('recipe'=>'pancakes', 'egg', 'milk', 'flour'));
var_dump(iterator_count($iterator));
?>
Powyższy przykład wyświetli:
int(4)
Przykład #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());
?>
Powyższy przykład wyświetli:
string(3) "one" int(3) NULL
Przykład #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";
}?>
Powyższy przykład wyświetli:
0: one (3)
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User Contributed Notes 2 notes
fractile81 at gmail dot com ¶
3 years ago
