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replacecoldfusion

coldfusion bug in Replace function

Here is my program:

<cfset test = 'a~b~~c~d~~~e'>
<cfset test2 = Replace(test, '~~','~X~','all')>
<cfoutput>  
        test  #test# 
   <br> test2 #test2# 
   <br>wanted: a~b~X~c~d~X~X~e
</cfoutput>

The output I got:

test a~b~~c~d~~~e  
test2 a~b~X~c~d~X~~e  
wanted: a~b~X~c~d~X~X~e

So the output of test2 is wrong This no doubt has to do with the inner workings of the Replace function, but I need it to work correctly.

Does anyone know of a workaround for this problem?

Solution

  • It's not a bug.

    Replace() doesn't have any special "lookaround" capability. It just walks the input string until it finds ~~. Then jumps to the next character - after the matched text - and continues searching. Resulting in only two matches.

    How Replace searches the string

    It sounds more like the requirement is to insert an "X" in between any two tildes "~~". A regex with a non-capturing look-ahead should accomplish that.

     reReplace(test, '~(?=~)','~X','all')

    Explanation

    • ~ Find tilde
    • (?=~) .. followed by another tilde

    Demo Example