What is the difference between call and apply?

Question

What is the difference between using call and apply to invoke a function?

var func = function() {
  alert(\'hello!\');
};
         


        

Answer 1

Let me add a little detail to this.

these two calls are almost equivalent:

func.call(context, ...args); // pass an array as list with spread operator

func.apply(context, args);   // is same as using apply

There’s only a minor difference:

• The spread operator ... allows passing iterable args as the list to call.
• The apply accepts only array-like args.

So, these calls complement each other. Where we expect an iterable, call works, where we expect an array-like, apply works.

And for objects that are both iterable and array-like, like a real array, we technically could use any of them, but apply will probably be faster because most JavaScript engines internally optimize it better.