Iterator::rewind
If Iterator::valid() returns false, the foreach() loop will be terminated.
Iterator::valid
(PHP 5 >= 5.0.0)
Iterator::valid — بررسی صحت موقعیت فعلی
Description
abstract public boolean Iterator::valid
( void
)
این متد پس از Iterator::rewind() فراخوانی خواهد شد و Iterator::next() برای بررسی صحت موقعیت فعلی است.
Parameters
This function has no parameters.
Return Values
مقدار بازگشتی به boolean تبدیل خواهد شد و ارزیابی میشود. Returns TRUE on success or FALSE on failure.
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User Contributed Notes
Iterator::valid - [3 notes]
seva dot lapsha at gmail dot com ¶
3 years ago
Voitcus at gmail dot com ¶
2 months ago
If your class implements also ArrayAccess interface, you could use as valid() body
function valid(){
return $this->offsetExists($this->position);
}
hyponiq at gmail dot com ¶
1 year ago
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)
?>