Flex Regular expression help needed

Question

I have created the regexp which allows me to enter == > (digit(0-9)).(digit(0-9) - for 2 decimal)

I am not sure how do I stop, to allow entering "0" more than once.

This is what i have tried:

/^[[0-9]]?[0-9]*\.?[0-9]{0,2}$/

But it also allows to enter value like 00000.2 , I wanted to stop user entering any value if its stars with 0. and allow only 0.2

Answer 1

Try this

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

See it here on Regexr

This allows 0 or a number starting with 1-9 before the dot. The fractional part is completely optional, but when it is existing, it need one or two digits after the dot.