In this short tutorial, I explain the concept of “back references” and explore how they are used to match the characters previously matched by capturing parentheses (groups) in a regular expression (regex).
This is the fifth video in a series on Regular Expressions, which is part of the “Programming from A to Z” course at ITP (
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Links discussed in this video:
MDN’s Regular Expressions Reference:
Regular Expressions on Wikipedia:
Book Mastering Regular Expressions:
ITP from Tisch School of the Arts:
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