Question

I had to split a string into his numbers.

For example the string looks like that:

VAR_1123 Var_G -12.34 VAR-14.34 12.4 12 -234

The result i’d like:

-12.34,
12.4
12
-234

I try this Regular Expression:

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

But the result includes also 1123 and -14.34.

How can i exclude all numbers that have an underscore or a character bevor?

For testing i use this link:

http://derekslager.com/blog/posts/2007/09/a-better-dotnet-regular-expression-tester.ashx

Answer 1

• Use parentheses instead of a character class to group the dot and the last digits.
• Use ?: to mean a non-capturing match.
• Change [\-] to simply -.
• Use lookaheads or lookbehinds to check for surrounding whitespace.

So the final regular expression looks like this:

(?<=\s|^)-?[0-9]+(?:\.[0-9]+)?(?=\s|$)

See it working online: ideone