![]() If the expression starts with a caret and ends with a dollar sign, the field must exactly match the pattern. If a dollar sign ($) is at the end of a pattern, the field must end with a string that matches the pattern. If a caret (^) is at the beginning of a pattern, the field must begin with a string that matches the pattern. If you want to ensure that the entire entry matches the pattern, “anchor” it to the beginning and end of the field, as follows: For example, it would match “is is”, but not “This is”.ĬoldFusion validation normally considers a value to be valid if any of it matches the regular expression pattern. This code matches text that contains a word that is repeated twice that is, it matches a word (specified by the \b word boundary special character and the “ )” followed by one or more spaces (specified by “ ”), followed by the first matched subexpression, the first word, in parentheses. The following example shows backreferencing in a regular expression: 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. A slash followed by a digit n (\n) refers to the nth parenthesized subexpression. [ ^ $ ( ) ” is not allowed.īackreferencing lets you match text in previously matched sets of parentheses. The following rules govern regular expressions that match a single character: For example, use two backslash characters (\\) to represent a backslash character. For information on regular expressions used in ColdFusion functions, see Using Regular Expressions in Functions.īecause special characters are the operators in regular expressions, to represent a special character as an ordinary one, escape it by preceding it with a backslash. These rules differ from the rules used by the ColdFusion functions REFind,REReplace,REFindNoCase, and REReplaceNoCase. Note: The rules listed here are for JavaScript regular expressions, and apply to the regular expressions used incfinputandcftextinputtags only. For example, you can validate against a value that you generate dynamically from other input data or database values. The ColdFusion server evaluates the variables and functions before the regular expression is evaluated. You can use ColdFusion variables and functions in regular expressions. You can concatenate simple regular expressions into complex search criteria to validate against complex patterns, such as any of several words with different endings. Regular expressions let you check input text for a wide variety of custom conditions for which the input must follow a specific pattern. The validation succeeds only if the user input matches the pattern. Ordinary characters are combined with special characters to define the match pattern. You can use regular expressions to match and validate the text that users enter in cfinput and cftextinput tags.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |