Regex to match whole word with a particular definition of a word

Question

I am doing a file search and replace for occurrences of specific words in perl. I\'m not usually much of a perl or regex user. I have searched for other regex questions here

Answer 1

See the example on this page which explains boundary matchers

Enter your regex: \bdog\b
Enter input string to search: The dog plays in the yard.
I found the text "dog" starting at index 4 and ending at index 7.

Enter your regex: \bdog\b
Enter input string to search: The doggie plays in the yard.
No match found.