is_numeric returning false on '0'

[bugzy]

Newbie question guys...

 

 

On my form

 

<?php<input type="text" name="item_stock" size="3" value="<?php if(isset($_POST['submit']) AND is_numeric($_POST['item_stock'])) { echo $item_stock; } ?>

 

I have this validation

 

then

 

<?php

$item_stock = me_mysql_prep(trim($_POST['item_stock']));


//validation

if(!is_numeric($_POST['item_stock']) AND !empty($_POST['item_stock']))
{
	$item_sto = '';
}
else
{
	$item_sto = "has stock";
}



?>

 

 

 

On the validation, it keeps telling me that '0' is not numeric. I also tried using is_int.. but it's not working also..

 

Anyone?

[xyph]

Are you sure it's not telling you it's empty?

 

<?php

$var = '0';

var_dump(is_numeric($var));
// outputs boolean true

var_dump(empty($var));
// outputs boolean true

?>

 

Are you sure your logic makes sense for that check?

[kyle04]

You need to ues :

 

if(!is_numeric($_POST['item_stock']) || !empty($_POST['item_stock']))

 

ie if not a number OR is empty = no stock

 

However, the value 0 returns a positive result so :

 

if(!is_numeric($_POST['item_stock']) || !empty($_POST['item_stock']) || $_POST['item_stock']==0) {

echo "no stock";

}

[Pikachu2000]

If you're trying to validate that a field contains only the digits 0-9, you should be using ctype_digit, since is_numeric() will return TRUE for '0XABCDEF' (hexadecimal number) as well as 83.956e45 (exponential notation).

[bugzy]

If you're trying to validate that a field contains only the digits 0-9, you should be using ctype_digit, since is_numeric() will return TRUE for '0XABCDEF' (hexadecimal number) as well as 83.956e45 (exponential notation).

 

Guys the problem is not is_numeric..

 

"0" digit will always return true using the empty function of php. I have tried

 

if != "";

 

Not working also.. Any other good alternative for empty function??

[Pikachu2000]

I wasn't saying that is_numeric was the problem. I was pointing out that you probably shouldn't be using it in the manner in which you are.

[btherl]

For this situation I typically use this combination:

 

if(!ctype_digit($_POST['item_stock']) || !($_POST['item_stock'] > 0))

 

That's for situations where I want an integer greater than 0.  The first check excludes anything other than positive integers, but still allows "" and "0".  The second check excludes "" and "0".  If you do this a lot you can make a function for it.

 

If this is a text input then I would also use trim() first, because a lot of people add space into text inputs boxes.

[bugzy]

Thanks guys.. solved it.