Creating an iterable in JavaScript

Let's create a real iterable object that can be iterated through a for-of loop. To do this, the object needs to add the appropriate function to Symbol.iterator.

Let's implement it. Let's have the following object:

javascriptlet obj = {
  a: 1,
  b: 2,
  c: 3,
};

We add a function to Symbol.iterator:

javascriptobj[Symbol.iterator] = function() {

}

And turn this function into a generator:

javascriptobj[Symbol.iterator] = function *() {

}

Inside our function, this will refer to the object itself:

javascriptobj[Symbol.iterator] = function *() {
  console.log(this); // the object itself
}

Let's start iterating over the object in the iterator:

javascriptobj[Symbol.iterator] = function *() {
  for (let key in this) {
    yield obj[key];
  }
}

That's it, the object can be iterated with a for-of loop:

javascriptfor (let elem of obj) {
  console.log(elem); // 1, 2, 3
}

Задание 1

Make an object that can be looped over with for-of. Let the loop element contain an object whose key key will contain a key of the object being iterated, and the val key will contain a value. An example:

javascriptlet obj = {a: 1, b: 2, c: 3};

for (let elem of obj) {
  console.log(elem);
}

It will output:

javascript{key: 'a', val: 1}
{key: 'b', val: 2}
{key: 'c', val: 3}