Regex Cheat Sheet/Optional group

Make an entire grouped piece optional.

Section: Groups and Alternation

Optional group

regex
regex
^(?:\+1[-.\s]?)?\d{3}[-.\s]?\d{3}[-.\s]?\d{4}$
Explanation

Common for optional prefixes in validators.

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Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

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Match one branch or another.
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Make the previous token optional.
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