Question

Please help me to make a Regular Expression with following rule –

1. Max number can be 9999.99
2. Should be non-negative
3. Can not be 0, but 0.01 and so on is valid
4. So, I need a non negative number between 0.01-9999.99

Answer 1

Erm, this isn’t really a job for Regexp, but it works with it anyway:

/(\d{2,4}(\.(\d[1-9])|([1-9]\d))?)|[1-9]/

A More strict evaluation would be:

/^([1-9]\d{,3}(\.\d{1,2})?)?|(0\.([1-9]\d?)|(0\.0[1-9]))$/

With not accepting leading zero’s, but allowing for just one decimal: “0.1”.
Bear in mind, decimals are optional.

I suggest, however, to use mathematical operations: Convert to float and then check:

if((num > 0) && (num < 100000)) {...}

You can use sprintf() to get the representation that you need, for instance limiting the number of decimals, etc.