Question

Hey I’m trying to perform input validation in PHP to ensure that the stock values that are typed in are at least 1 positive integer and from 0-9. Should not contain any special characters.

For example, any of the following values should be valid:

7
0
32
47534

The following SHOULD NOT be valid:

asdf
35/gdf
../34.

etc..

I’m using the following if statement to check for the positive integer value of “$original_stock”.

if (preg_match("/^[0-9]$/", $original_stock)) 
{
    $error .="Original stock must be numerical.";
}

Additionally, I have a price field which should be validated as either an int or a double.

If there’s an easier alternative to using regex, that’s okay too!

Thanks in advance 🙂

Answer 1

Try this regexp:

/^\d+$/

The issue with your existing regexp is that it only matches strings with exactly one digit.

As for validating an int or a double:

/^\d+\.?\d*$/

Note that that regexp requires that there be at least one digit.