• "str₁"~~"str₂"~~… yields an ordinary string obtained by concatenating the characters in the "str_i".
• The following objects can appear in StringExpression :
• "string" a literal string of characters
  _ any single character
  __ any substring of one or more characters
  ___ any substring of zero or more characters
  x_, x__, x___ substrings given the name x
  x:pattern pattern given the name x
  pattern.. pattern repeated one or more times
  pattern... pattern repeated zero or more times
  {patt₁,patt₂,…} or patt₁|patt₂|… a pattern matching at least one of the patt_i
  AnyOrder [patt₁, patt₂, …] a pattern matching all of the patt_i in any order
  FixedOrder [patt₁, patt₂, …] a pattern matching the concatenation of the patt_i
  patt/;cond a pattern for which cond evaluates to True
  pattern?test a pattern for which test yields True for each character
  Whitespace a sequence of whitespace characters
  NumberString the characters of a number
  DatePattern [spec] the characters of a date
  charobj an object representing a character class (see below)
  RegularExpression ["regexp"] substring matching a regular expression
  StringExpression[…] an arbitrary string expression
• The following represent classes of characters:
• {c₁,c₂,…} any of the "c_i"
  Characters ["c₁c₂…"] any of the "c_i"
  CharacterRange ["c₁","c₂"] any character in the range "c₁" to "c₂"
  HexadecimalCharacter hexadecimal digit 0-9, a-f, A-F
  DigitCharacter digit 0–9
  LetterCharacter letter
  WhitespaceCharacter space, newline, tab, or other whitespace character
  WordCharacter letter or digit
  Except [p] any character except ones matching p
• The following represent positions in strings:
• StartOfString start of the whole string
  EndOfString end of the whole string
  StartOfLine start of a line
  EndOfLine end of a line
  WordBoundary boundary between word characters and others
  Except [WordBoundary ] anywhere except a word boundary
• When constructs like __ or .. are present, there may be several different ways in which a given StringExpression can match a particular string.
• By default, the Wolfram Language will use the one that makes pattern elements that appear earlier in the StringExpression match the longest possible substrings.
• The following determine which match will be used if there are several possibilities:
• Shortest [p] the shortest consistent match for p
  Longest [p] the longest consistent match for p (default)
• In matching ordinary expressions instead of strings, the shortest instead of the longest consistent match is used.
• StringExpression objects can be used in many string manipulation functions, including StringReplace , StringCases , StringSplit , and StringMatchQ .
• StringExpression has attributes Flat and OneIdentity .

Basic Examples  (2)

Scope  (5)

Applications  (1)

Properties & Relations  (1)