JavaScript check if value is only undefined, null or false

Question

Other than creating a function, is there a shorter way to check if a value is undefined,null or false only in JavaScript?

Answer 1

One way to do it is like that:

var acceptable = {"undefined": 1, "boolean": 1, "object": 1};

if(!val && acceptable[typeof val]){
  // ...
}

I think it minimizes the number of operations given your restrictions making the check fast.