Iterator::key

(PHP 5, PHP 7)

Iterator::keyDevuelve la clave del elemento actual

Descripción

abstract public Iterator::key ( void ) : scalar

Devuelve la clave del elemento actual.

Parámetros

Esta función no tiene parámetros.

Valores devueltos

Devuelve scalar en caso de éxito, o NULL en caso de error.

Errores/Excepciones

Muestra un E_NOTICE en caso de error.

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User Contributed Notes 3 notes

up
7
michaelgranados at gmail dot com
7 years ago
Since PHP 5.5.X foreach can accept non scalar items. So the return can be anything ;)
up
-1
sofe2038 at gmail dot com
1 month ago
This function may return any type, not just scalar, for some Iterator types. In particular, it is very trivial to write a generator function that yields arbitrary keys:

<?php
function foo() {
  yield
null => 1;
  yield new
stdclass => 2;
}
?>
up
-1
Lszl Lajos Jnszky
8 years ago
And converts everything to integer except string, so in php the post process could be:

    public function key() {
        $yourKey = $this->createYourKey();
        if (is_object($yourKey) || is_array($yourKey))
            throw new Exception('Array and Object not allowed.');
        elseif (is_string($yourKey))
            return $yourKey;
        else
            return (int) $yourKey;
    }
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