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JavaScript Regular Expressions in JavaScript Regular Expressions Beginning and Ending of Strings

Posted by Vivian Centeno
Vivian Centeno
2,655 Points

Regex exercise(Group)

I am trying the second exercise, I have this ^(img_) (jpg|png|gif)$ cannot seem to validate the middle part. Thank you in advance! Match:

img_01.jpg img_02.png img_03.gif img_04.png img_05.gif img_06.jpg

Exclude: mov_01.avi

1 Answer

Jesse Vorvick
Jesse Vorvick
6,047 Points
Jesse Vorvick
Jesse Vorvick
6,047 Points

In case you are still curious, what you typed doesn't validate the middle part because the middle part isn't typed. The ^ includes everything after it, including the (jpg|png|gif), while the $ includes everything before it, including the (img_). Think of the ^ and the $ like quotes in the specific way that you have used it. So you effectively have told the computer to search for literally (img_)(jpg|png|gif) with no exceptions, which means nothing with a "middle part" will show up.

An alternative (and perhaps overly simplified) way to search would be something like ^(img_)....(jpg|png|gif)$

You could also do something like ^(img_)_\d{2}.(jpg|png|gif)$ to be extra specific.

Hope that helps!