Question

I’m working on a new Java project and therefore im reading the already existing code. On a very important part of the code if found the following regex expression and i can’t really tell what they are doing. Anybody can explain in plain english what they do??

1)

 [^,]*|.+(,).+

2)

(\()?\d+(?(1)\))

Answer 1

1)

[^,]* means any number of characters that are not a comma
.+(,).+ means 1 or more characters followed by a comma followed by 1 or more characters
|  means either the first one or the second one

2)

(\()? means zero or one '('  note* backslash is to escape '('
\d+ means 1 or more digits
(?(1)\)) means if back-reference \1 matched, then ')' note* no else is given

Also note that parenthesis are used to capture certain parts of the regular expression, except, of course, if they are escaped with a backslash