How to check if arbitrary object type is an Image

[AlexK]

Try this as a workaround:

Why doesnt this work

Interesting, @hasanchik . Image is an interface, not a class, and instanceof does not work with interfaces in TypeScript. The traditional way to deal with this is to typecast the variable and check for an interesting method. That, though, does not work in MakeCode. [image] So, the next best thing is to check for an interesting attribute instead. This works: let a: Image = img`.` let b: number = 42 let msg: string = "" function testImage(i: any): boolean { if ((<Image>i).width) { …