Fun quiz!!!

quiz-4-1.js

Object.prototype.objCustom = function() {}; 
Array.prototype.arrCustom = function() {};

let a = [3, 5, 7];
a.x = 'hello';

Object.defineProperty(a, 'y', {});
Object.defineProperty(a, 'z', {
  enumerable: true
});

for (let i of a) {
  console.log(i); 
}
// What will console print?

quiz-4-2.js

Object.prototype.objCustom = function() {}; 
Array.prototype.arrCustom = function() {};

let a = [3, 5, 7];
a.x = 'hello';

Object.defineProperty(a, 'y', {});
Object.defineProperty(a, 'z', {
  enumerable: true
});

for (let i in a) {
  console.log(i); 
}
// What will console print?

quiz-4-3.js

Object.prototype.objCustom = function() {}; 
Array.prototype.arrCustom = function() {};

let a = [3, 5, 7];
a.x = 'hello';

Object.defineProperty(a, 'y', {});
Object.defineProperty(a, 'z', {
  enumerable: true
});

for (let i in a) {
  if (a.hasOwnProperty(i)) console.log(i);
}
// What will console print?

quiz-4-4.js

let obj = {
  x: 1, 
  y: "hello", 
  z: {a : 1},
  t: [1, 2]
};

Object.freeze(obj);

obj.x = 2;
obj.y = "bye";
obj.z.a = 2;
obj.t[0] = 3;
obj.t[1] = 4;

console.log(obj);
// What will console print?

quiz-4-5.js

let obj = {
  x : 1, 
  y : "Hi",
  z : function() {
    console.log(this.x, this.y);
  }
};

let str = JSON.stringify(obj);
console.log(str);
// What will console print?

quiz-4-6.js

let a = {y: 1};
a.x = a;

let str = JSON.stringify(a); 
console.log(str);