About metacharacter

[Jianan_luna]

I am currently taking advanced programming course now. I am super confused about the usage of metacharacter. When I did the level 2 practice for course 2, I cannot makes sense the answer, and I don't know how to comprehend and create this metacharacter. Can you please help me figure it out? Thanks so much!

[ChrisNZ]

This is a PERL Regular Expression.

\b means a word boundary (the end or start of a word).

There are countless tutorials on the web.