Word boundary

Usually a regular expression match the word, even that is embedded in other word.

For Example

Enter Regular Expression

repeat

Enter the string

Don't repeat the repeated things

I found the text repeat starting at index 6 Ending at index 12

I found the text repeat starting at index 17 Ending at index 23

In the string 'Don't repeat the repeated things', regular expression matches the word twice, first one from the word 'repeat' and second one from the word 'repeated'.

By using '\b' you can specify the boundary for the word.

Enter Regular Expression

repeat\b

Enter the string

Don't repeat the repeated things

I found the text repeat starting at index 6 Ending at index 12

But the same regular expression match the word 'repeat' in the string 'prepeat'.

Enter the string

prepeat

I found the text repeat starting at index 1 Ending at index 7

So to exactly match the word 'repeat' use the regular expression '\brepeat\b'.

Enter Regular Expression

\brepeat\b

Enter the string

Don't repeat the repeated things

I found the text repeat starting at index 6 Ending at index 12

Enter the string

prepeat

Enter the string

repeat repeated

I found the text repeat starting at index 0 Ending at index 6

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