Question

I created the following conditional regex which seems to work at http://gskinner.com/RegExr/ but doesn’t compile in Java.

The regex is as follows :

X: (\d+). Y: (\d+)(?(?=:inherit=(true|false)))

And it is supposed to pull my X, Y value and (if exists) the value followed by the :inherit=

e.g

X: 192131, Y: 1923123 (matches 192131, 1923123)

X: 192131, Y: 1923123:inherit=true (matches 192131, 1923123, true)

X: 192131, Y: 1923123:inherit=false (matches 192131, 1923123, false)

In Java I get an error:

Unknown inline modifier near index 20 X: (\d+). Y: (\d+)(?(?=:inherit=(true|false))) 

With index 20 being the second parenthesis in (?(?

Can someone help me get it right in Java, and maybe also explain why the website tester processes it.

Thanks!

Answer 1

(?( is not a valid syntax.

Use:

X:\s(\d+),\sY:\s(\d+)(?::inherit=(true|false))?

You need to escape \.