Iterator::valid

(PHP 5 >= 5.0.0)

Iterator::valid — Checks if current position is valid

Description

abstract public boolean Iterator::valid ( void )

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

Parameters

This function has no parameters.

Return Values

The return value will be casted to boolean and then evaluated. Returns TRUE on success or FALSE on failure.

add a note User Contributed Notes Iterator::valid

hyponiq at gmail dot com 26-Sep-2011 10:12


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 12:19


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

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