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I am using the function match for a search engine, so whenever a user types a search-string I take that string and use the match function on an array containing country names, but it doesn't seem to work.

For example if I do :

var string = "algeria";
var res = string.match(/alge/g); //alge is what the user would have typed in the search bar
alert(res);

I get a string res = "alge": //thus verifying that alge exists in algeria

But if I do this, it returns null, why? and how can I make it work?

var regex = "/alge/g";
var string = "algeria";
var res = string.match(regex);
alert(res);
fejese
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Codious-JR
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4 Answers4

3

To make a regex from a string, you need to create a RegExp object:

var regex = new RegExp("alge", "g");

(Beware that unless your users will be typing actual regular expressions, you'll need to escape any characters that have special meaning within regular expressions - see Is there a RegExp.escape function in Javascript? for ways to do this.)

Community
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RichieHindle
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  • Was just typing the same. In the original post var regex = "/alge/g" is a string, not a regular expression :) – PeteAUK Jun 04 '14 at 14:38
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You don't need quotes around the regex: 

var regex = /alge/g;
akxlr
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Remove the quotes around the regex.

              var regex = /alge/g;
              var string = "algeria";
              var res = string.match(regex);
              alert(res);
Lynxy
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found the answer, the match function takes a regex object so have to do 

             var regex = new RegExp(string, "g");
            var res = text.match(regex);

This works fine

Codious-JR
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