
Using backreferences
153
Using backreferences in replacement strings
You can use backreferences in the replacement string of both the
REReplace
and
REReplaceNoCase
functions. For example, to replace the first repeated word in a text string with
a single word, use the following syntax:
REReplace("There is is a cat in in the kitchen",
"([A-Za-z ]+)\1","\1")
This results in the sentence:
“There is a cat in in the kitchen”
You can use the optional fourth parameter to
REReplace
,
scope
, to replace all repeated words, as in
the following code:
REReplace("There is is a cat in in the kitchen",
"([A-Za-z ]+)\1","\1","ALL")
This results in the following string:
“There is a cat in the kitchen”
The next example uses two backreferences to reverse the order of the words "apples" and "pears"
in a sentence:
<cfset astring = "apples and pears, apples and pears, apples and pears">
<cfset newString = REReplace("#astring#", "(apples) and (pears)",
"\2 and \1","ALL")>
In this example, you reference the subexpression (apples) as \1 and the subexpression (pears) as \2.
The
REReplace
function returns the string:
"pears and apples, pears and apples, pears and apples"
Note:
To use backreferences in either the search string or the replace string, you must use
parentheses within the regular expression to create the corresponding subexpression. Otherwise,
ColdFusion throws an exception.
Using backreferences to perform case conversions in replacement
strings
The
REReplace
and
REReplaceNoCase
functions support special characters in replacement
strings to convert replacement characters to uppercase or lowercase. The following table describes
these special characters:
To include a literal \u, or other code, in a replacement string, escape it with another backslash; for
example \\u .
Special
character Description
\u
Converts the next character to uppercase.
\l
Converts the next character to lowercase.
\U
Converts all characters to uppercase until encountering \E.
\L
Converts all characters to lowercase until encountering \E.
\E
End \U or \L.
Содержание ColdFusion MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...