Redirect non-www to www in .htaccess

Question

I have this in my .htaccess file:

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

but whenever I

Answer 1

I have tested all the above solutions but not working for me, i have tried to remove the http:// and won't redirect also removed the www it redirect well, so i get confused, specially i am running all my sites under https://

So i have combined some codes together and came up with perfect solution for both http:// and https:// and www and non-www.

# HTTPS forced

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]
# Redirect to www
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [R=301,L]

Hope this can help someone :)