Question

I have been trying for hours to work out a solution for this problem. Let say there is a string

"hello Exclude1 4:32  test test Exclude2 5:23 hello 2:19 some more text 42:3 more text"

I am trying to create a C# regx which will only match 2:19 and 42:3
but ignore Exclude1 4:32 and Exclude2 5:23

i.e don’t match 4:32 or n:nn if it is preceded by Exclude1 or Exclude2.
Thanks

Answer 1

You can use a negative lookbehind to ignore an expression preceeded by some other expression:

(?<!Exclude1 )(?<!Exclude2 )\d+:\d+

This will match ##:## that is not immediately preceeded by either Exclude1  or Exclude2 .

Demos: Regular Expression | C# Code Sample