单个.htaccess用于多个页面重定向与不同的URL

Question

i am changing my website and its old pages were like bellow

http://mydomain.com/keyword_city.html

while i read that its better to use - in page for batter SEO, so i am thinking to use new new page name like bellow

http://mydomain.com/keyword-city.html

first of all i want to know is this better idea to change page URL? and if i change my URL does this effect on page ranking ?

i want to know how to write single .htaccess so that any request coming for old page will redirect to new URL, the only difference in old and new URL will be _ to -

Thanks

Answer 1

The following code added to .htacess should redirect all underscores _ to hyphens -

RewriteRule (.*)_(.*) $1-$2 [N]