Last Updated: February 15, 2022
· ready4god2513

Ruby Regex

I have a mission. I have been programming for quite a few years, but have always passed at really digging deep in to regex. No longer.

I am going to use this as a placeholder for some of my newfound knowledge. First, I use rubular for testing my expressions. Second, a great resource has been this article by bluebox

So without further ado, here we go-

Match a single character- /(.)/ If we used "testing 123" as our match we would have 11 matches. "testing 123".scan(/(.)/)

Match a group of (any) characters- /(.+)/ This will keep matching until we either come to the end of the line or add another match in.

Positive lookahead /test(?=ing)/ will match testing, but not testers or test. The match will return just the word test.

Positive lookbehind /(?<=wel)come/ will match welcome but not become

The lookahead and lookbehind assertions also have a negative matcher, which can be invoked by replacing the = with the ! character, like so /(?<!wel)come/. That will match become but not welcome.

That's all for now, but I will keep on searching, and keep on coding.

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Awesome, thanks.

over 1 year ago ·