Alphabet used in regular expressions

Name Conventional designation Usage example
Any character * "c"*"t" allows such words as cat, cot, etc.
Letter C C"ot" allows such words as Rot, pot, cot, Dot, mot, etc.
Uppercase letter A A"ot" allows such words as Rot, Cot, Mot, Dot, etc.
Lowercase letter a a"ot" allows such words as rot, cot, mot, dot, etc.
Letter or number X X allows any standalone number or letter.
Number N N"th" allows such words as 5th, 4th, 6th, etc.
String " " "cot"
Or | "pl"("o"|"a")"t" allows words "plot" and "plat".
Character from group [] [tm]"ot" allows words "tot" and "mot".
Character not from group [^] [^t]"ot" allows words "cot", "lot", etc., but does not allow the word "tot".
Space (within group) \s [A\s] allows only the letter A or a space.

Any number of repetitions

(applies to the expression or subexpression on the left)

{-} [AB74]{-} allows any combinations of characters A, B, 7, 4 of any length.
Number of repetitions n {n} N{2}"th" allows such words as 25th, 84th, 11th, etc.
From n to m repetitions {n-m} N{1-3}"th" allows such words as 5th, 84th, 111th, etc.
From 0 to n repetitions {-n} N{-2}"th" allows such words as 84th, 5th, etc.
From n repetitions and more {n-} N{2-}"th" allows such words as 25th, 834th, 311th, 34576th, etc.
Subexpression ()
Hyphen symbol [\-]
Slash symbol [\\]

Examples of regular expressions:

  1. Postal code: [0-9]{6}
    An sample value: "142172"
  2. Zip code (USA): [0-9]{5}("-"[0-9]{4}){-1}
    Sample values: "55416", "33701-4313"
  3. Income: N{4-8}[,]N{2}
    Sample values: "15000,00", "4499,00"
  4. Month in the numerical form: ((|"0")[1-9])|("10")|("11")|("12")
    Sample values: "4", "05", "12"
  5. Fraction: ("-"|)([0-9]{1-})(|(("."|",")([0-9]{1-})))
    Sample values: "1234,567", "0.99", "100,0", "-345.6788903"
  6. E-mail: [A-Za-z0-9_]{1-}(("."|"-")[A-Za-z0-9_]{1-}){-3}"@"[A-Za-z0-9_]{1-}(("."|"-")[A-Za-z0-9_]{1-}){-4}"."([A-Za-z]{2-4}|"asia"|"museum"|"travel"|"example"|"localhost")
    Sample values: "support@abbyy.com", "my-name@company.org.ru", "info@gallery.museum"

4/12/2024 6:16:02 PM

Please leave your feedback about this article

Usage of Cookies. In order to optimize the website functionality and improve your online experience ABBYY uses cookies. You agree to the usage of cookies when you continue using this site. Further details can be found in our Privacy Notice.