Regex matches which are not followed by a string

Question

I am using the following regex for detecting negative numbers:

([-]([0-9]*\.[0-9]+|[0-9]+))

But I want to skip the matches which are followed by $. If i use the folowing regex:

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

It will match correctly the positions but will include the following character. For example in expression:

-0.6+3 - 3.0$

it will match:

-0.6+

I want to match only

-0.6

Answer 1

You can use the regex from Regular-Expressions.info with just minus at the beginning, and a \b added at the end in order to stop before any non-word character:

[-][0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?\b

This regex also captures the numbers with exponent part.

See demo

Answer 2

Remove the $ from the group:

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

You could use this simplified regex:

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

Answer 3

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

You need a negative lookahead here which will not consume and only make an assertion.