CachingIterator::__construct — Construir un nuevo objeto CachingIterator para el iterador
CachingIterator::count — El número de elementos en el iterador
CachingIterator::current — Devuelve el elemento actual
CachingIterator::getCache — Recuperar el contenido de la caché
CachingIterator::getFlags — Obtener las banderas utilizadas
CachingIterator::hasNext — Comprueba que el iterador interno tenga un elemento siguiente válido
CachingIterator::key — Devuelve la clave del elemento actual
CachingIterator::next — Desplaza el iterador adelante
CachingIterator::offsetExists — Comprobar existencia de un índice
CachingIterator::offsetGet — El propósito offsetGet
CachingIterator::offsetSet — El propósito offsetSet
CachingIterator::offsetUnset — El propósito offsetUnset
CachingIterator::rewind — Rebobina el iterador
CachingIterator::setFlags — El propósito de setFlags
CachingIterator::__toString — Devolver la representación en formato cadena del elemento actual
CachingIterator::valid — Comprueba que el elemento actual sea válido

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User Contributed Notes 4 notes

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ahmad dot mayahi at gmail dot com ¶

4 years ago

The only difference between CachingIterator and other Iterators such as ArrayIterator is the hasNext() method.

Since the data will be loaded into the memory, the CachingIterator is able to check whether the given iterator has a next element.

Let's demonstrate this by an example:

<?php
$iterator = new CachingIterator(new ArrayIterator(['C', 'C++', 'C#', 'PHP', 'Python', 'Go', 'Ruby']));

foreach ($iterator as $item) {
    if ($iterator->hasNext()) {
        echo $item.', ';
    } else {
        echo 'and '.$item;
    }
}

// C, C++, C#, PHP, Python, Go, and Ruby
?>

In this example I check whether the iterator has a next value, if so, I append a comma otherwise "and" will be appended to the last element.

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ahmad dot mayahi at gmail dot com ¶

8 years ago

<?php
//This snippet will print out all the cached elements (foreach) .

$cache  = new CachingIterator(new ArrayIterator(range(1,100)), CachingIterator::FULL_CACHE);

foreach ($cache as $c) {

}

print_r($cache->getCache());
?>

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jerome at chaman dot ca ¶

4 years ago

"cached iteration over another iterator" means this iterator is always one step behind the inner iterator. In other words, the "first" iteration will yield null:

<?php

$cit = new CachingIterator( new ArrayIterator( [ 'a', 'b', 'c']  ) );

echo $cit->current() ); // null
echo $cit->getInnerIterator()->current() ); // "a"

while($cit->hasNext()){
    
    // we start with a "next" since the "first" item is null
     $cit->next();
     echo $cit->current(), '<br>';
   
}
?>

iterating this way gives us an access, ahead, to the future item (aka current item of the inner iterator)

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xedin dot unknown at gmail dot com ¶

4 years ago

Apparently, the `FULL_CACHE` flag automatically cancels the default flag `CALL_TOSTRING`. This is evident when one of the values cannot be converted to string: with the default `CALL_TOSTRING` flag, it would throw an error; without that flag, or with the `FULL_CACHE` flag, it does not.

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