MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Руководство по разработке, Страница: 612 / 860

612 Chapter 27: Building Dynamic Forms
•
The dollar sign ($) at the end of a regular expression matches the end of the field.
•
The concatenation of regular expressions creates a regular expression that matches the
corresponding concatenation of strings. For example, [A-Z][a-z]* matches any capitalized
word.
•
The OR character (|) allows a choice between two regular expressions. For example, jell(y|ies)
matches either "jelly" or "jellies".
•
Braces ({}) are used to indicate a range of occurrences of a regular expression, in the form {m,
n} where m is a positive integer equal to or greater than zero indicating the start of the range
and n is equal to or greater than m, indicating the end of the range. For example, (ba){0,3}
matches up to three pairs of the expression "ba". The form {m,} requires at least m occurrences
of the preceding regular expression. The form {m} requires exactly m occurrences of the
preceding regular expression. The syntax {,n} is not allowed.
Backreferences
Backreferencing lets you match text in previously matched sets of parentheses. A slash followed by
a digit n (\n) refers to the
n th parenthesized subexpression.
One example of how you can use backreferencing is searching for doubled words; for example, to
find instances of ‘the the’ or ‘is is’ in text. The following example shows the syntax you use for
backreferencing in regular expressions:
(\b[A-Za-z]+)[ ]+\1
This code matches text that contains a word (specified by the \b word boundary special character
and the [A-Za-z]+) followed by one or more spaces [ ]+, followed by the first matched
subexpression in parentheses. For example, it would match “is is, or “This is is”, but not “This is”.