Simple regular expression for a decimal with a precision of 2

Question

What is the regular expression for a decimal with a precision of 2?

Valid examples:

123.12
2
56754
92929292929292.12
0.21
3.1

Answer 1

In general, i.e. unlimited decimal places:

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