JavaScript Function Objects and this Quiz

Review

1. What makes a function object callable?

   A callable object has a [[Call]] internal method.
2. Which statement is correct?

   Every constructor has [[Construct]] and is therefore also a function object with [[Call]].
3. For obj.read(), what supplies this to an ordinary read function?

   A property-reference call uses the base object as the this value.
4. Why can const fn = obj.read; fn() lose obj as this?

   The standalone call no longer has obj as the property-reference base.
5. What does a strict ordinary function do with a supplied null this value?

   Strict ordinary functions use the supplied this value as-is.
6. Why can call() not replace an arrow function’s this?

   Arrow functions have lexical this and do not create their own this binding.
7. How does apply() differ from call() in argument passing?

   apply() converts its second argument into an argument list, while call() receives arguments individually.
8. What does bind() return?

   bind() creates a new bound function for later calls.
9. What does new require from its target?

   The target must support [[Construct]], meaning it is a constructor.
10. Passing task to run(task) rather than task() passes what?

    Without parentheses, the function value itself is passed as an argument.