Dealing with variable and underscore

here is the problem about parsing the variable from URL

And I tried to use $cat in the PHP like this

SELECT from DATABASE while $cat_review

I want the $cat added with \'_review\'

how to do that ? I know it\'s simple question, but I can\'t figure it out 🙁

Thanks

You want the value of cat (currently book) to be appended with the text "_review", correct?

$cat .= "_review";

Then run your query using just $cat.

Do you want to use a variable named $cat_review? If so that is exactly what you are doing.

no, i want to use variable phrase from the url combine with "_review"

so when i phrase from the url like
?cat=toy

i want the query from toy_review (database)

?cat=food

i want the query from food_review (database)

so do you think
$cat .= "_review";
will works ?

Yes $cat .= "reveiw"; will work. All it is doing is concatinating the text "review" to the end of the value inside the $cat variable.