What does "1\/1." mean in Ruby?

Question

I am learning Ruby and I have something to match with (/^1\/1. Guess a word from an anagram [RUBY]{4}$/)

Please, what does "1\/1." mean in this expression. Can anyone explain what's going on for me.

Thanks

Does this answer your question? [Reference - What does this regex mean?](https://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean) — Karl Knechtel, Jul 19 '22 at 18:41
This isn't actually a question about Ruby. Many languages use regular expressions, with a common (or extremely similar) syntax. — Karl Knechtel, Jul 19 '22 at 18:42

score 2 · Answer 1 · answered Jul 19 '22 at 18:42

Generally speaking, a backslash in a regular expression escapes the next character, so that it's treated as an ordinary character rather than whatever its special meaning would be. For instance a* matches zero or more of the letter a, but a\* matches, literally, an a followed by a star. Since most regular expressions in Ruby are wrapped in the delimiter /, we can't directly put forward slashes in our regex. If we had written

/^1/1. Guess a word from an anagram [RUBY]{4}$/

Then the regex would be /^1/ and the rest of the line would be a very confusing syntax error. This is for the same reasons that we can't put " characters directly inside of a "-delimited string.

So a backslash treats it as an actual slash in the expression rather than a delimiter.

/^1\/1. Guess a word from an anagram [RUBY]{4}$/

We're literally matches a 1 followed by a slash followed by a 1 at the start of the line.

Your explanation was so helpful. Thanks so much – Adesuyi Fisola Jul 19 '22 at 19:11 — Adesuyi Fisola, Jul 19 '22 at 19:11

What does "1\/1." mean in Ruby?

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