Regex match optional string greedy inbetween two random strings-CodePudding

I am looking for a way to match an optional ABC in the following strings. Both strings should be matched either way, if ABC is there or not:

precedingstringwithundefinedlenghtABCsubsequentstringwithundefinedlength precedingstringwithundefinedlenghtsubsequentstringwithundefinedlength

I've tried

.*(ABC).*

which doesn't work for an optional ABC but making ABC non greedy doesn't work either as the .* will take all the pride:

.*(ABC)?.*

This is NOT a duplicate to e.g. Regex Match all characters between two strings as I am looking for a certain string inbetween two random string, kind of the other way around.

CodePudding user response：

I’ve come up with an answer myself: Using the OR operator seems to work:

(?:(?:.*(ABC))|.*).*

If there’s a better way, feel free to answer and I will accept it.

CodePudding user response：

You could use this regex: .*(ABC){0,1}.*. It means any, optional{min,max}, any. It is easier to read. I can' t say if your solution or mine is faster due to the processing speed.