Each of the arguments required by the function, must be in the array supplied in the third argument to iterator_apply. You can use references too. Example:
<?php
function translate_to(string $target_language, Iterator $words, array $dictionaries) {
$language = ucfirst($target_language);
$dictionary = $dictionaries[$target_language] ?? 'not found';
if ($dictionary === 'not found') {
echo "Not found dictionary for {$language}\n";
return;
}
echo "English words translated to {$language}\n";
$not_found = [];
iterator_apply($words, function($words, $dictionary, &$not_found){
$english_word = $words->current();
$translated_word = $dictionary[$english_word] ?? '';
if ($translated_word !== '') {
echo "{$english_word} translates to {$translated_word}\n";
} else {
$not_found[] = $english_word;
}
return true;
}, array($words, $dictionary, &$not_found));
echo "\nNot found words:\n" . implode("\n", $not_found) . "\n";
}
$dictionaries = [
'nahuatl' => [
'one' => 'Ze',
'two' => 'Ome',
'three' => 'Yei',
'four' => 'Nahui',
],
];
$iterator = new \ArrayIterator(array('one', 'two', 'three', 'four', 'gasoil'));
translate_to('nahuatl', $iterator, $dictionaries);
?>
English words translated to Nahuatl
one translates to Ze
two translates to Ome
three translates to Yei
four translates to Nahui
Not found words:
gasoil
iterator_apply
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
iterator_apply — ユーザー関数をイテレータのすべての要素でコールする
説明
イテレータ内のすべての要素に対して関数をコールします。
パラメータ
-
iterator -
順次処理したいイテレータオブジェクト
-
callback -
すべての要素に対してコールしたいコールバック関数。 この関数は
argsのみを受け取ります。 デフォルトでは引数を渡されません。 たとえばcount($args) === 3の場合、 コールバック関数は3変数関数です。注意:
iteratorでの処理を続けるために、 この関数はtrueを返さなければなりません。 -
args -
コールバック関数に渡す引数。 引数の array。
argsの個々の要素が コールバックcallbackに別々の引数として渡されます。
戻り値
イテレータの要素数を返します。
例
例1 iterator_apply() の例
<?php
function print_caps(Iterator $iterator) {
echo strtoupper($iterator->current()) . "\n";
return TRUE;
}
$it = new ArrayIterator(array("Apples", "Bananas", "Cherries"));
iterator_apply($it, "print_caps", array($it));
?>上の例の出力は以下となります。
APPLES BANANAS CHERRIES
add a note
User Contributed Notes 3 notes
tezcatl at fedoraproject dot org ¶
6 years ago
tezcatl at fedoraproject dot org ¶
6 years ago
Be aware of the proper methods to iterate the specific Iterator you are consuming, as the implementation of the method could vary its behaviour.
For example, unlike the ArrayIterator, you can't iterate on a SplDoubleLinkedList with current() without using next() on every iteration (and then, only would iterate if you return true at the end of the callable. It is far easier then with LinkedLists use a while($it->valid()) { $it->current(); $it->next(); }
Let's see:
<?php
$ll = new \SplDoublyLinkedList();
$ll->push('ze');
$ll->push('ome');
$ll->push('yei');
$ll->push('nahui');
$ll->rewind();
$iterations_done = iterator_apply($ll, function(Iterator $it) {
echo implode("\t=>", [
$it->key(),
$it->current(),
ucfirst($it->current())
]),"\n";
return true;
}, array($ll));
echo "Did iterate {$iterations_done} times \n";
$ll->rewind();
$iterations_done = iterator_apply($ll, function(Iterator $it) {
echo implode("\t=>", [
$it->key(),
$it->current(),
ucfirst($it->current())
]),"\n";
$it->next();
return true;
}, array($ll));
echo "Did iterate {$iterations_done} times \n";
$ll->setIteratorMode(SplDoublyLinkedList::IT_MODE_FIFO | SplDoublyLinkedList::IT_MODE_DELETE);
var_dump($ll->count());
foreach($ll as $key => $val) {
echo "{$key}\t",ucfirst($val),"\n";
}
var_dump($ll->count());
?>
Output:
0 =>ze =>Ze
0 =>ze =>Ze
0 =>ze =>Ze
0 =>ze =>Ze
Did iterate 4 times
0 =>ze =>Ze
1 =>ome =>Ome
2 =>yei =>Yei
3 =>nahui =>Nahui
Did iterate 4 times
int(4)
0 Ze
0 Ome
0 Yei
0 Nahui
int(0)
ycgambo at outlook dot com ¶
6 years ago
$args is an array and each of its elements are passed to the callback as separate arguments.
so this is the right way to get args:
<?php
$ai = new ArrayIterator(range(0, 2));
iterator_apply($ai, function() {
var_dump(func_get_args()); // use this func
return true;
}, array(1, 2));
?>
output:
array(2) {
[0] =>
int(1)
[1] =>
int(2)
}
array(2) {
[0] =>
int(1)
[1] =>
int(2)
}
array(2) {
[0] =>
int(1)
[1] =>
int(2)
}
--------------------------------------------------
or list each args:
<?php
$ai = new ArrayIterator(range(0, 2));
iterator_apply($ai, function($arg1, $arg2, $arg3) {
var_dump([$arg1, $arg2, $arg3]);
return true;
}, array(1, 2));
?>
same output.
