Regex Matching numbers with floating point

Question

I have this pattern:

[0-9]*\\.?[0-9]

It matches numbers but it also matches 3.5.4 as:

1. 3.5
2. .4

How to f

Answer 1

You have to decide if you want to accept numbers without leading zeros (eg .123). If you don't then the regex is easy:

^-?[0-9]+(\.[0-9]+)?$

If you do then it's a little more complex:

^-?(?:[0-9]+|[0-9]*\.[0-9]+)$

Both presume that a decimal point must be followed by at least one digit. If you don't accept negative numbers then the leading -? is unnecessary.