404 error with .htaccess url slug without a hyphen - regex

Question

I'm new to .htaccess and I've been working on a site where I have used URL slugs. Everything is working perfectly fine with slugs that have hyphens in them, but I get 404 error when I have a one word slug.
https://www.example.com/blog/example-blog works fine but https://www.example.com/blog/example throws a 404 error.
Below is the .htaccess code I'm currently using:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteRule ^([a-z]+)\/?$ $1.php [NC]
RewriteRule ^([a-zA-Z0-9-]+)\/?$ index.php?url=$1 [NC]
RewriteRule ^([a-zA-Z0-9-]+)\/season\/([0-9]+)\/?$ index.php?url=$1&season=$2 [NC]
</IfModule>
I've searched everywhere on Search Engine but got no luck. Any help is highly appreciated.
Summary:
I'm looking for ways for .htaccess to accept a slug without a hyphen as those with hyphens are working fine.

Answer 1

RewriteRule ^([a-z]+)\/?$ $1.php [NC]
This rule will catch the request /example and unconditionally rewrites it to example.php. Whereas /example-blog (with a hyphen) is ignored by this rule (because the regex ^([a-z]+)\/?$ does not match).
If this rule is required then add an additional condition that checks for the existence of the .php file before rewriting (otherwise this rule should be removed altogether). For example:
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^([a-z]+)/?$ $1.php [NC,L]
Now, only requests that actually map to .php files are rewritten.
UPDATE:
I've added the L flag to the above rule, although it will still work without.
So, in summary, your complete set of rules should look like this:
RewriteEngine On
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^([a-z]+)/?$ $1.php [NC,L]
RewriteRule ^([a-zA-Z0-9-]+)/?$ index.php?url=$1 [L]
RewriteRule ^([a-zA-Z0-9-]+)/season/([0-9]+)/?$ index.php?url=$1&season=$2 [L]
There's no need to backslash-escape slashes in the regex, so I've removed the unnecessary backslashes. The NC flag is superfluous on the last two rules since you are already matching a-zA-Z in the RewriteRule pattern. And I've added the L flag, since you want processing to stop after the rewrite.
The <IfModule> container is also not required.