Strange JavaScript Regular Expression Behavior

Posted by Kiwi on Stack Overflow See other posts from Stack Overflow or by Kiwi
Published on 2010-06-14T04:12:03Z Indexed on 2010/06/14 4:22 UTC
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JavaScript

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regex

I'm getting different behavior from a regular expression in JavaScript depending on whether or not I declare it using literal syntax. Using a extremely simple test HTML file:

<html>
    <head>
        <script type="text/javascript">
            var s = '3';
            var regex1 = /\d/;
            var regex2 = new RegExp('\d');

            alert(s.search(regex1)); //  0 (matches)
            alert(s.search(regex2)); // -1 (does not match)
        </script>
    </head>
    <body></body>
</html>

The regular expression declared with literal syntax (/\d/) works correctly, while the other (new RegExp('\d')) does not. Why on earth is this happening?

I'm using Google Chrome 5.0.375.70 on Windows Vista Home Premium, if that's at all helpful.

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