javascript number regular expression

Question

I've come up with this regular expression to validate a javascript number according to the specification:

(-|\+|)(\d+\.?\d*|\.\d+)([eE](-|\+|)\d+)?

As far as I can think of, these are valid numbers in js:

123,123.3, .3, -123, -.3, -.3e-2, -.3e+2, +.2e2... and so forth.

I've been trying to find a verified regular expression on the internet so that I could compare my solution but to no avail.

Could anyone tell me if my approach is correct or give me a better solution?

Link to test my solution

Answer 1

While using isNan is the correct way of checking numbers in JavaScript, you can also validate floating point numbers with [-+]?[0-9]*\\.?[0-9]+(?:[eE][-+]?[0-9]+)? regex (taken from Regular-Expressions.info ).

Consider using appropriate anchors though! ( ^ for string start, $ for string end).

Demo is available here .