I was reading this example of using a for.. of loop on a Map, and I was a bit confused with this syntax:

var myMap = new Map();

myMap.set(0, zero);

myMap.set(1, one);



for (var [key, value] of myMap) {

  console.log(key +  =  + value);

}

Specifically, I don't understand the array destructuring that is happening. I understand that you can use array destructuring to do something like let [one, two] = [1, 2];, but what is happening in this example? myMap isn't an array so why is this getting the correct values?

Another question I have is why is the order key, value in the destructuring, but when you do a forEach() the order is value, key, like here:

myMap.forEach((value, key) => {

  console.log(key +  =  + value);

});