how to remove .php extension fro php file using htaccess

RewriteCond %{REQUEST_FILENAME} !-d

RewriteRule ^([^/]+)/$ http://www.letsdemat.com/$1 [R=301,L]

# Redirect external .php requests to extensionless url

RewriteCond %{THE_REQUEST} ^(.+)\.php([#?][^\ ]*)?\ HTTP/

RewriteRule ^(.+)\.php$ http://www.letsdemat.com/$1 [R=301,L]

# Resolve .php file for extensionless php urls

RewriteRule ^([^/.]+)$ $1.php [L]