How to revert .htaccess changes - apache

Question

Im running apache with xampp. I've done some changes to hide files' type at link. After a while I noticed that adding href with directory, adds same directory again to link like so:
/dir into /dir/dir and then dir/dir/dri ....
and for hrefs at current directory, it sends me to certain page - page that was in script for .htaccess. Guess it's been because my IDE autosaves file as I add it and it had overriden defaults before I've set the right properties.
Code that I put to .htaccess:
RewriteEngine On
# Unless directory, remove trailing slash
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^/]+)/$ http://example.com/folder/$1 [R=301,L]
# Redirect external .php requests to extensionless URL
RewriteCond %{THE_REQUEST} ^(.+)\.php([#?][^\ ]*)?\ HTTP/
RewriteRule ^(.+)\.php$ http://example.com/folder/$1 [R=301,L]
# Resolve .php file for extensionless PHP URLs
RewriteRule ^([^/.]+)$ $1.php [L]
Can I somehow revert this changes / go back to default?
If I delete file, try to override with similar code it still doesn't fix the problem.

Answer 1

DirectorySlash Off
RewriteEngine on
RewriteCond %{THE_REQUEST} \s/+(.*?/)?(?:index)?(.*?)\.(php|html)[\s?/] [NC]
RewriteRule ^ /%1%2 [R=302,L,NE]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*) /$1.php [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME}\.html -f
RewriteRule ^(.*) /$1.html [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !\/$
RewriteRule ^(.*) %{REQUEST_URI}/ [L,R=302]
This works - Extension goes off and works with new files and directories. Previous one I can't repair...