Whether the wildcard character represents a single character or a string of characters must be specified.
Computing
In computer (software) technology, a wildcard character can be used to substitute for any other character or characters in a string. The asterisk (*) usually substitutes as a wildcard character for any zero or more characters, and the question mark (?) usually substitutes as a wildcard character for any one character, as in the command line interpreters of CP/M, DOS, Microsoft Windows and Unix-likeoperating systems. This is referred to as glob expansion. In SQL, wildcard characters can be used in "LIKE" expressions; the percent sign (%) matches zero or more characters, and underscore (_) a single character. In Microsoft Access, wildcard characters can be used in "LIKE" expressions; the asterisk sign (*) matches zero or more characters, and question mark (?) a single character. In many regular expression implementations, the period (.) is the wildcard character for a single character.