Is there a reason why some images won't upload using this script?

[imgrooot]

I am using this script for image uploads.

 

https://www.w3schools.com/php/php_file_upload.asp

 

I noticed that with some of the image uploads, I would get the error 

"Sorry, only JPG, JPEG, PNG & GIF files are allowed."

 

The images i upload are one of the file types listed above.  So I am wondering why i would get an error for some images but not others despite all them of being the same file types?

 

Can you tell why judging from the script?

 

 

[imgrooot]

I found what the issue was. 

 

This code in the script has all lowercase extensions.

if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg" && $imageFileType != "gif") {}

I had to also add all the UPPERCASE extensions as well. And it worked.

if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg" && $imageFileType != "gif" && $imageFileType != "JPG" && $imageFileType != "PNG" && $imageFileType != "JPEG" && $imageFileType != "GIF") {}

[benanamen]

Doubling the amount of code you are using is not the answer. strtolower is your friend.

 

Checking just the file extension is also not a good idea. A user can put any file extension they want. Doesn't mean it is a valid file type.  You should also be checking the file mime type.

 

Put the extensions in an array and then use in_array to validate. Same with the mime types.

 

w3schools is not the best place to learn from.

Edited December 10, 2017 by benanamen

[imgrooot]

Doubling the amount of code you are using is not the answer. strtolower is your friend.

 

Checking just the file extension is also not a good idea. A user can put any file extension they want. Doesn't mean it is a valid file type.  You should also be checking the file mime type.

 

Put the extensions in an array and then use in_array to validate. Same with the mime types.

 

w3schools is not the best place to learn from.

 

Copy. I will keep that in mind. Thanks.