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JavaScript Regular Expressions by Gabriel Manricks, Loiane Groner

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Defining multipliers in Regex

Matchers are great but they only "scale" your pattern in one direction. I like to think of matchers as things that scale your pattern vertically, allowing you to match many more strings that fit into the same pattern, but they are still constrained in length, or scale the pattern horizontally. Multipliers allow you to match arbitrarily sized strings that you may receive as input, giving you a much greater range of freedom.

There are three basic multipliers in Regex:

  • +: This matches one or more occurrences
  • ?: This matches zero or one occurrence
  • *: This matches zero or more occurrences

We will cover these three multipliers in this section, and also show you how to create a custom multiplier.

Matching one or more occurrences ...

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