• Previous metacharacters can be repeated 0, 1 or an infinite number of times.
  • However, there are cases where you’ll want to repeat something a certain number of times.
  • {
    • Start quantified repetition of preceding item.
  • }
    • End quantified repetition of preceding item.
    • {min,max}
  • min and max are always positive numbers.
  • min must always be included and can be zero.
  • max is optional.
  • Three syntaxes:
    • \d{4,8} matches numbers with 4 to 8 digits.
    • \d{4} matches numbers with exactly 4 digits (min is max).
    • \d{4,} matches numbers with 4 or more digits (max is infinite).
  • \d{0,} is the same as \d*
  • \d{1,} is the same as \d+
  • /\d{3}-\d{3}-\d{4}/ matches most US phone numbers.
  • /A{1,2} bonds/ matches “A bonds” and “AA bonds”, but not “AAA bonds”.
  • A good example:
  • /\d\. \w+\s/
    • \s indicates the line return at the end and the above regex matches the following:
      1. a
      2. ab
      3. abc
      4. abcd
      5. abcde
      6. abcdef
  • Changing the above regex to:
  • /\d\. \w{2,5}\s/ would match all of the above words that are 2~5 characters long.

Updated: