correct 301 redirect methord???

can anyone pls tell me the correct version of the 301 redirect code from following 3, 301 redirect codes???

example 1 (currently using)
-------------------------------------------------
RewriteEngine ON
RewriteCond %{HTTP_HOST} !^(.*).example.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]

example 2
-------------------------------------------------
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^http://example.com[NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]


example 3
-------------------------------------------------
RewriteEngine On
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]



I prefer www version instead of non www version and I m currently using example 1 code..


is there any difference between these 3 codes???

 

RewriteEngine On
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]

is the correct way to redirect non-www version to www version.

 

I'm using this way:

# BEGIN WordPress
<IfModule mod_rewrite.c>

Options +Indexes
Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
RewriteCond %{HTTP_HOST} ^www\.xxxxxxxxxxx\.xxx [NC]
RewriteRule ^(.*)$ http://xxxxxxxxxxx.xxx/$1 [R=permanent,L]
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ http://www.xxxxxxxxx.xxx/$1/ [L,R=301]
</IfModule>

# END WordPress

 

Hi guys

I have seen at many place to redirect url
code is

redirect301"/domin.html" http://www.domin.com

Please tell me where it will be use and what about

RewriteEngine On
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]

please guied me

 

When there is an option of choosing between www n non www domain name in wordpress admin panel, why would be there any need of this redirect? n do we need to add this redirect in htaccess always? or there are special circumstances? e.g first we see our search results n if there are duplicate contents in search results then add this redirect in our htaccess?

 

RewriteEngine On
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]


is a best way