how to reduce complexity in regex?

Question

I have a regex which finds all kind of money denoted in dollars,like $290,USD240,$234.45,234.5$,234.6usd

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


        

Answer 1

Reducing the complexity you are reducing the correctness. The following regex works correctly, but even it doesn't take lowcase. (but that could be managed by a key). All other current answers here simply haven't the correct substring for the decimal number.

^\s*(?:(?:(?:-?(?:usd|\$)|(?:usd|\$)-)(?:(?:0|[1-9]\d*)?(?:\.\d+)?(?<=\d)))|(?:-?(?:(?:0|[1-9]\d*)?(?:\.\d+)?(?<=\d))(?:usd|\$)))\s*$

Look here at the test results.

Make a correct line and only after that try to shorten it.