How can I use regex to match a string with several ending values including no end value?

I’m trying to come up with with a regex statement that will match and not match the following cases:

CT.test                  // (1) must match
CT.test (MONT)           // (2) must match
CT.test (ABS)            // (3) must match
CT.badsf                 // (4) must not match
CT.test (WOW)            // (5) must not match

I’ve tried CT.test( \(MONT\)| \(ABS\)|^$) but that only matches cases 2 and 3 and not case 1.

What is a regex statement that will match case 1, 2 and 3 and not match cases 4 and 5?

>Solution :

You can use

^CT\.test(?: \((?:MONT|ABS)\))?$

See the regex demo

See the details here:

• ^ – start of string
• CT\.test – (note the escaped dot): a CT.test string
• (?: \((?:MONT|ABS)\))? – an optional sequence of
  • – a space
  • \( – a ( char
  • (?:MONT|ABS) – MONT or ABS string
  • \) – a ) char
• $ – end of string.