• Example character sets –>
    • /[0123456789]/
      • Matches any ONE number.
    • /[abcdefghijklmnopqrstuvwxyz]/
      • Matches any ONE lowercase character.
    • /[ABCDEFGHIJKLMNOPQRSTUVWXYZ]/
      • Matches any ONE uppercase character.
  • However if you wanted to match all 3 of the above, it would be a very long string.
  • - range of characters.
    • This is a metacharacter.
  • Can do it with letters, numbers and symbols.
  • If a - is outside square brackets, it is a literal dash.
  • Examples:
    • [0-9]
    • [A-Za-z]
  • Caution:
    • [50-99] is not all numbers from 50 ~ 99.
      • It is only going to match a single character.
      • It cannot target two characters.
        • This would be the same expression as [0-9]
        • The regex engine will read it as a character set, which would include 5, 0-9 and 9.
        • Its not a number range, its a character range.
  • If you want to match a phone number, you can repeat this 3 times:
  • Example: /[0-9][0-9][0-9]-[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]/
    • This would match “555-666-7890”
      • Works well with ID numbers, zip codes and so on.

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