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JavaScript

Posted by teamz
teamz
44,723 Points

How is it possible that Regex can change a const?

I am a little confused by this video. I get that regex functions can be used to test constants but I was surprised as it looks like the regex used on a constant changed the constant. (***The example shared was modifying corn dog to hot dog.)

I thought that constants are not change-able?

Can someone please help me better understand?

1 Answer

Steven Parker
Steven Parker
243,318 Points
Steven Parker
Steven Parker
243,318 Points

You didn't provide a link to the video, but without seeing it I would guess that you may have misinterpreted the demonstration. My guess is that the regex is being used to create a changed copy of the constant but the original constant remains unmodified.

Please provide a link to the video and an approximate time reference if that doesn't explain it.

teamz
teamz
44,723 Points

Hi Steven--

Sorry about that, I had thought the question was being asked out of the video in question.

Here is the link:

https://teamtreehouse.com/library/using-regular-expressions-in-javascript

I was doing great until right about 2:03 where they were changing the const string1. I really thought that this would throw an error as it was set up with a const and not a let.

Thanks for taking time to help me understand! :)

Steven Parker
Steven Parker
243,318 Points
Steven Parker
Steven Parker
243,318 Points

It looks like I guessed correctly. According to the MDN page on the replace method:

The replace() method returns a new string with some or all matches of a pattern replaced by a replacement. The pattern can be a string or a RegExp, and the replacement can be a string or a function to be called for each match.
 
Note: The original string will remain unchanged.