Welcome to Regex-Inception

We're so glad you made it down the rabbit hole. You've reached the part of the regex engine where the recursion gets real.

Deep Down Shallow

Here's a simple regex that will match any string that contains the word "shallow":

/.*shallow.*/

Try it out:

Or, if you're feeling extra clever, try this more complex regex that matches any string that contains the word "shallow" in the middle:

/.*shallow.*/

And for the true regex wizards out there, try this one on for size:

/.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*shallow.*sh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(Note: This regex is not actually meant to be used, but is instead meant to illustrate the concept of recursion in regex. It's like the regex equivalent of a recursive function in programming, but with more semicolons.)

What's next?

Want to try another regex? Here's one that matches any string that contains the word "shallow" in the middle, but this time with a more complex pattern: