Wildcards for Text
|*||No or several characters.|
|?||Any single character.|
|#||Any single numeral (0 - 9).|
|[charlist]||Any single character in charlist.|
|[!charlist]||Any single character that isn't contained in charlist.|
The wildcards can be combined in any sequence.
The following characters have to be inserted in square brackets in order to be used for a compare operation: left square bracket ([), question mark (?), pound sign (#) and asterisk (*). The right square bracket (]) can't be used in a string of characters being compared. However, it can be indicated outside of a string as an individual character.
You can also specify a range of characters in charlist by indicating the largest and smallest value of the range, separated by a hyphen (-). For example, [A-Z] results in a match if the respective character position in charlist is a letter between A and Z. You can specify a sequence of several ranges in square brackets without using separators.
Other key rules for using wildcards:
- An exclamation point (!) at the beginning of charlist means that a match results when any character except for the characters in charlist is found. If the exclamation point is used outside of the square brackets it serves as a wildcard for itself.
- A hyphen (-) can appear at the beginning (after an exclamation point, if present) or at the end of charlist in order to serve as a wildcard for itself. In any other position a hyphen serves to designate a character range.
- When a range of characters is specified, the characters have to be listed in ascending order (from the lowest to the highest). This means that [A-Z] is a permissible pattern whereas [Z-A] isn't.
|Type of correspondence||Text||Correspondence||No correspondence|
|Several characters||a*a||aa, aBa, aBBBa||aBC|
|*ab*||abc, AABB, Xab||aZb, bac|
|[ ? # *||a[*]a||a*a||aaa|
|Several characters||ab*||abcdefg, abc||cab, aab|
|Individual characters||a?a||aaa, a3a, aBa||aBBBa|
|Individual numerals||a#a||a0a, a1a, a2a||aaa, a10a|
|Character range||[a-z]||f, p, j||2, &|
|Outside of range||[!a-z]||9, &, %||b, a|
|No numerals||[!0-9]||A, a, &, ~||0, 1, 9|
|Combination||a[!b-m]#||An9, az0, a99||abc, aj0|