How to use mod_rewrite for redirecting www and non www address to same page

From a SEO perspective it is a good idea to redirect your site from a non www address (http://example.com) to the www prefixed version (http://www.example.com).

Here is how can you do that:

You must edit or if you do not have one create the file .htaccess (the leading dot must be included) in the root of your website and place the following code in it:

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