javascript how to loop an array and use the value only as the key for an object code example

Example 1: javascript iterate over object

var obj = { first: "John", last: "Doe" };

Object.keys(obj).forEach(function(key) {
    console.log(key, obj[key]);
});

Example 2: how to iterate through a js object

let object = {
  x: 10,
  y: 10,
  z: 10
};
let keys = Object.keys(object);
// now 3 different ways:
  // method 1:
  key.forEach(function(key){
      let attribute = object[key];
      // do stuff
    }
  );

  //method 2:
  for(let key of keys){
    let attribute = object[key];
    // do stuff
  }

  //method 3:
  for(let i = 0; i < keys.length; i++){
    let key = keys[i];
    let attribute = object[key];
    // do stuff
  }