AI Frontend · Exercise 1 of 5Next
Beginner
Check a File Before You Accept It
A file picker lists the files a person chooses. Write validate(file) so it returns a sentence when the file must be refused, and null when it is fine. The page already shows the accepted names in #list and the sentences in #error.
Refuse, in this order: an empty file (<name> is empty.), a file bigger than 1 MB (<name> is too big.), and any type other than image/png or image/jpeg (<name> is not a PNG or JPEG.). Use the file's name, size and type.
What Check tests
- A normal PNG is listed and no error shows
- An empty file is refused with
<name> is empty. - A file over 1 MB is refused with
<name> is too big. - A GIF is refused with
<name> is not a PNG or JPEG. - A good and a bad file together: the good one is still listed
Stuck? One hint at a time
The solution unlocks after your first Check. Try first: that is where the learning happens.
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