Question

What's the output?

function sayHi() {
  return (() => 0)();
}

console.log(typeof sayHi());

• A: "object"
• B: "number"
• C: "function"
• D: "undefined"

Answer 1

Answer: B

The sayHi function returns the returned value of the immediately invoked function expression (IIFE). This function returned 0, which is type "number".

FYI: typeof can return the following list of values: undefined, boolean, number, bigint, string, symbol, function and object. Note that typeof null returns "object".