Supposing you have a string that starts with a number, e.g. “25% discount this weekend”, and you’re using that along with a regular expression. If you’ve got a backreference immediately prior to that “25%…”, ColdFusion treats it as \125 instead of \1.
<cfset myString = "25% Discount this weekend"> <cfset originalString = "Look out for our special offers, including XXX and much more"> <cfset newString = reReplace(originalString, "(.*)XXX(.*)", "\1#myString#\2")> <cfoutput>#newString#</cfoutput>
This just outputs:
% Discount this weekend and much more
as it thinks that you’re trying to do \125 instead of \1 followed by “25%…”
To get around this, you can use \E to separate the backreference from the rest of the string.
\E is meant to indicate when you’ve reached the end of an uppercase or lowercase block as set by \U or \L. However in this case it simply indicates to the regular expression process where the end of the backreference occurs.
<cfset newString = reReplace(originalString, "(.*)XXX(.*)", "\1\E#myString#\2")> <cfoutput>#newString#</cfoutput>
This time it correctly outputs:
Look out for our special offers, including 25% Discount this weekend and much more