regular expression for valid 2 digit decimal number

Question

I want to have a validation in php for price which can be 100 or 100.45 The 2 decimal places will be optional.

Now the validation should allow only digits.

S

Answer 1

Lacks a $ in your regex. Presently, the first 3 characters in '100a...' match your regex.

preg_match('/^[0-9]+(\.[0-9]{1,2})?$/', "100")

should do the trick.

Answer 2

Try this:

if (!preg_match('/^[0-9]+(\.[0-9]{1,2})?$/', "100"))

The $ denotes the "end of a string": http://www.php.net/manual/en/regexp.reference.meta.php