Check if variable holds File or Blob

Question

Javascript has both File and Blob for file representation, and both are almost the same thing. Is there a way to check if a variable is holding a File or a Blob type of data?

Answer 1

Easiest way:

a = new File([1,2,3], "file.txt");
b = new Blob([1,2,3]);
c = "something else entirely";

a instanceof File
> true
b instanceof File
> false
c instanceof File
> false