Regex for optional comma separated number with decimal point

Question

I\'m after a regular expression which will match the following

1,245.30
24,235,235.50
12235235.60
235.50

The decimal is mandatory but I\'d

Answer 1

Um, just allow a number without commas as an explicit alternative:

^(\d?\d?\d(,\d\d\d)*|\d+)(\.\d\d)?$