Is checking the type of files sufficient?

Question

PHP

Users have the ability to upload pictures to the site. Is such a check on the pictures enough?

if  ((( $_FILES [ "file" ][ "type" ]  ==  "image/gif" ) 
||  ( $_FILES [ "file" ][ "type" ]  ==  "image/jpeg" ) 
||  ( $_FILES [ "file" ][ "type" ]  ==  "image/jpg" ) 
||  ( $_FILES [ "file" ][ "type" ]  ==  "image/png" ))

Answer 1

The most effective option is to prohibit the execution of code from the downloads folder. For example, using rules in .htaccess.

Answer 2

habrahabr.ru/post/44610