Preg Match decimal point

Hi Guys,

I have a form field that i need verifying. Im currently using the following to check that only numbers have been entered.

if (preg_match('/[0-9\s]/', $price))
{
$error[] = "The price you have entered is invalid!<br />";
}

However id like to allow a decimal point / full stop in the text field, as well as validate that there are only 2 numbers after the decimal point if one has been entered.

Does anybody have any ideas how to modify the above code to allow this?

Many thanks.

Before offering up a hand with the decimals, are you aware that your current regular expression only makes sure that the price has a single digit or whitespace character (space, tab, etc.) but can contain any other characters as well?  For example "this is not a number" will be accepted! Can you see why?

Have you had a stab at allowing decimals yourself? Either way, take a moment to browse around a reference site [1] and try to familiarize yourself with the regex approach to problem solving (not everyone gets it).  Have a stab at it yourself; folks here much prefer teaching people to fish (or, code) over giving others a free meal (though, if you're lucky!).

[1] E.g. http://www.regular-expressions.info

Hi Salathe,

Sorry I missed out the ^ in the code above, it should have read:

if (preg_match('/[^0-9\s]/', $price))

It should only accept numbers now (i have absolutely no clue why). With regards to white space, when i create the variable I use ltrim and rtrim.

I tried to get my head round regex a few days ago, simply to make find and replace easier for me in dreamweaver, i found it that mind boggling and confusing that in the end i gave up.

Iv managed to get it to accept the decimal place by adding \. to make the code:

if (preg_match('/[^0-9\.\s]/', $price))

I still cant figure out how to make it accept up to 2 decimal places.

try

<?php
$price = '  123.3';
if(preg_match('/^\s*\d*\.?\d{1,2}\s*$/', $price)) echo "ok"; else echo "no";
?> 

try

<?php
$price = '  123.3';
if(preg_match('/^\s*\d*\.?\d{1,2}\s*$/', $price)) echo "ok"; else echo "no";
?> 

Thanks mate it works perfectly, Thanks!!!