Question

I have a JavaScript function where someone can pass anything in, and I iterate over each of its keys using the

for x in obj

syntax. However, this results in an error if they pass a primitive (string or number); the correct behavior is for the function to act the same way on those as it would on an object with no keys.

I can do a try..catch block to get around this, but is there another (more succinct) way?

Answer 1

x && typeof(x) === 'object'

This is true for objects and arrays (though you usually don’t want to iterate over arrays with for..in).

EDIT: Fix, per CMS.