Reg Exp failure for open parenthesis - Error - Unterminated parenthetical

[Alan Wells]

I'm trying to search for a function name with the following code and getting an error.  I want to include the first parenthesis in the search.

I'm getting the error:

SyntaxError: Unterminated parenthetical

  for (i = L-1;i>-1; i--){
    thisName = allNames[i];//The function name
   
    re = new RegExp('function ' + thisName + "(","g");//Create Reg Exp
   
    arrMatches = fileContentAsStr.match(re);//Search the entire file content for the fnk name
  }

I've tried:

re = new RegExp('function ' + thisName + "\(","g");//Same error

which produces the same error

and

re = new RegExp('function ' + thisName + "\\(","g");//No error but doesn't find anything




which doesn't cause an error but doesn't find anything

[Alan Wells]

If I use "search" instead of "match" with double escape it works.

[--Hyde]

Hi Alan,

The last variant you quote should work. Your regex will require the ( to be escaped, and JavaScript string literal handling will have turned \( into ( by the time it reaches RegExp, so you will have to double escape the string literal as in \\( to let RegExp see it as \(. Cannot say why the regex will not match function names in fileContentAsStr, but perhaps that is a white space or case-sensitivity issue. Try something like this:

var re = new RegExp('function\\s+' + thisName + '\\s*\\(', 'gi');

For regex testing, https://regex101.com/ is worth a visit — but keep in mind that the double escapes will have to be removed there.

Cheers --Hyde

[Alan Wells]

Thank you for the help.

That doesn't give me an error anymore, and most of the time it works.

I got a couple of unexpected results that I don't understand at all.  I'm trying something different with indexOf as a work around.

[AD:AM]

You may need to enable multiline processing, by including the m flag.