Add commas into number strings (RegEx)

In numbers of more than three digits, it's general to use a comma after every third digit from right to left. If you want to add commas into really many number strings, the following regular expression will be useful:

Find: (?<=\d)(?=(?:\d\d\d)+(?!\d))

Replace: ,

The following figure shows how it actually works in the RegexBuddy application.

Inserting commas into number strings

For more information on the regular expressions, please visit the site (

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