Regex for numbers only

Question

I haven\'t used regular expressions at all, so I\'m having difficulty troubleshooting. I want the regex to match only when the contained string is all numbers; but with the

Answer 1

Here is my working one:

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

And some tests

Positive tests:

string []goodNumbers={"3","-3","0","0.0","1.0","0.1","0.0001","-555","94549870965"};

Negative tests:

string []badNums={"a",""," ","-","001","-00.2","000.5",".3","3."," -1","--1","-.1","-0"};

Checked not only for C#, but also with Java, Javascript and PHP