How to escape regular expression's special characters using javascript?

Question

GaneshKumar1508 0 Newbie Poster

14 Years Ago

HI to all,

I am in need of escaping the regular expression special characters like '/', '.', '*', '+', '?', '|','(', ')', '', '{', '}', '\\'.

I have try with this by the following javascript but i can not achieve that.

RegExp.escape=function(str)
            {
                if (!arguments.callee.sRE) {
                    var specials = [
                        '/', '.', '*', '+', '?', '|',
                        '(', ')', '[', ']', '{', '}', '\\'
                    ];
                    arguments.callee.sRE = new RegExp(
                    '(\\' + specials.join('|\\') + ')', 'gim'
                );
                }
                return str.replace(arguments.callee.sRE, '\\');   
           
                }
                function regExpFind() {
//            var regex = new RegExp("\\[munees\\]","gim");
                  var regex=RegExp.escape("[Munees]waran");
                    alert("Reg : "+regex);          
                    alert(regex.exec("[Munees]waran"));
                }

If i go with the line which is commented,

var regex = new RegExp("\\[munees\\]","gim");

I have the correct output.
But by with the replace method i cannot achieve that?
Please guide me to achieve that.

javascript

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13 Replies
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Latest Post 14 Years Ago Latest Post by GaneshKumar1508

fxm 23 Posting Pro

14 Years Ago

var regex=RegExp.escape("[Munees]waran");

To generate a RegExp you need to change that to

var regex= new RegExp(RegExp.escape("[Munees]waran"));

Whether the resulting RegExp will do what you are trying to do isn't clear (to me, anyway).

fxm 23 Posting Pro

14 Years Ago

What is the input?
What output are you expecting?
What are you getting?

fxm 23 Posting Pro

14 Years Ago

If the problem is that you are expecting (after my prior fix) that the first alert will show this Reg : /\[Munees\]waran/ but it is showing this Reg : /\Munees\waran/ instead, then the cure is to change line 12 as follows

return str.replace(arguments.callee.sRE, '\\$1');

Edited 14 Years Ago by fxm because: n/a

fxm 23 Posting Pro

14 Years Ago

Any other way to achieve what?

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GaneshKumar1508 0 Newbie Poster · Answer 1 · 2010-06-15T07:27:34+00:00

Hi fxm,

I will try your code.But it's not give the output what i expect.Is there any other way to achieve this?

GaneshKumar1508 0 Newbie Poster · Answer 2 · 2010-06-15T16:20:47+00:00

Hi fxm,

Thanks for your efoorts.And i have update my code with your assistance but i got the following one,

Reg : /[Munees]waran/ instad of
  Reg : /\[Munees\]waran/

Is there any other way to achieve this?

GaneshKumar1508 0 Newbie Poster · Answer 3 · 2010-06-15T19:20:25+00:00

Hi fxm,

Thank you once again for your reply.

I need to get the output as

Reg:/\[Munees\]waran/

But i got

Reg:/[Munees]waran/

so i need to achieve /\[Munees\]waran/.So please help to get the expected output?

Thanks again.

fxm 23 Posting Pro · Answer 4 · 2010-06-15T19:26:37+00:00

If you applied each of the fixes I gave you, you would be getting what you need.

Please post the code you are now using.

GaneshKumar1508 0 Newbie Poster · Answer 5 · 2010-06-16T07:18:59+00:00

Hi fxm,

Here i post my code for your reference,

<%@page contentType="text/html" pageEncoding="ISO-8859-9"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
    "http://www.w3.org/TR/html4/loose.dtd">

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-9">
        <title>JSP Page</title>
        <script type="text/javascript">
            /**
             * Function for escape regular expression special characters.
             */
            RegExp.escape=function(str)
            {
                if (!arguments.callee.sRE) {
                    var specials = [
                        '/', '.', '*', '+', '?', '|',
                        '(', ')', '[', ']', '{', '}', '\\'
                    ];
                    arguments.callee.sRE = new RegExp(
                    '(\\' + specials.join('|\\') + ')', 'gim'
                );
                }
                return str.replace(arguments.callee.sRE, '\\$1');

            }
function regExpFind() {         
                    var regex= new RegExp(RegExp.escape("[Munees]waran"));
                    alert("Reg : "+regex);
                    alert(regex.exec("[Munees]waran"));
                }
        </script>
    </head>
    <body>
        <input type="button" value="Click" onclick="regExpFind()"/>
    </body>
</html>

I have got the output as Reg:/[Munees]waran/
But i need to get /\[Munees\]waran/
Please guide me to achieve this.
Thanks once again for all your efforts.

fxm 23 Posting Pro · Answer 6 · 2010-06-16T09:30:31+00:00

The first alert in the code you just posted displays Reg : /\[Munees\]waran/ What is the problem?

GaneshKumar1508 0 Newbie Poster · Answer 7 · 2010-06-16T10:50:06+00:00

Hi fxm,

This first alert only displayed only
Reg: /[Munees]waran/
The second alert displayed null

fxm 23 Posting Pro · Answer 8 · 2010-06-16T16:08:26+00:00

Those outputs are from your original page with the errors.
The outputs from the corrected page you just posted are Reg : /\[Munees\]waran/ and [Munees]waran .

GaneshKumar1508 0 Newbie Poster · Answer 9 · 2010-06-17T07:12:36+00:00

Hi fxm,

Can you post that code?Because i don't get the mentioned one.