Iterator::valid

(PHP 5 >= 5.0.0)

Iterator::valid — Checks if current position is valid

Descrierea

abstract public boolean Iterator::valid ( void )

This method is called after Iterator::rewind() and Iterator::next() to check if the current position is valid.

Parametri

Această funcție nu are parametri.

Valorile întoarse

The return value will be casted to boolean and then evaluated. Întoarce valoarea TRUE în cazul succesului sau FALSE în cazul eșecului.

add a note User Contributed Notes Iterator::valid

hyponiq at gmail dot com 26-Sep-2011 04:12


Take consideration when utilizing this method and using the returned value of isset([value]). The value of isset([value]) will be false for null values.



I ran into this problem when checking isset([value]) against array elements whose value was null.



Example:

<?php

$array = array(null, 1, 2, 3);

$isSet = isset($array[0]);

var_dump($isSet); // output: boolean(false)



class AClass {

    public $array = (null, 1, 2, 3);

    function valid() {

        return isset($this->array[0]);

    }

}



$class = new AClass;

var_dump($class->valid()); // output: boolean(false)

?>

seva dot lapsha at gmail dot com 01-Aug-2009 06:19


If Iterator::valid() returns false, the foreach() loop will be terminated.

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