What does Object.keys(person) return if var person = {name: 'John', age: 30};?

What will the following code output? console.log(person['age']); if var person = {name: 'John'};

A). 30

B). John

C). undefined

D). null

What is the output of console.log(person.greet()); if var person = {greet: function() {return 'Hello';}};?

A). Hello

B). Undefined

C). Error

D). Hello

What is the correct way to create an object in JavaScript?

A). var obj = {};

B). var obj = [];

C). var obj = ();

D). var obj = <>;

What will console.log(car.make); output if var car = {make: 'Toyota', model: 'Corolla'};?

A). Toyota

B). Corolla

C). Undefined

D). Error

What will console.log(newCar.make); output if class Car { constructor(make) { this.make = make; }} var newCar = new Car('Honda');?

A). Honda

B). Car

C). Undefined

D). Error

How do you inherit properties and methods from another class in JavaScript ES6?

A). class SubClass extends SuperClass {}

B). class SubClass inherits SuperClass {}

C). class SubClass implements SuperClass {}

D). class SubClass super SuperClass {}

How do you define a class in JavaScript ES6?

A). class ClassName { constructor() {} }

B). function ClassName() { constructor() {} }

C). class ClassName() { constructor {} }

D). function class ClassName { constructor() {} }

How do you call a method from a parent class in a subclass in JavaScript ES6?

A). super.methodName()

B). this.methodName()

C). parent.methodName()

D). base.methodName()

How do you define a method inside a class in JavaScript ES6?

A). methodName() {}

B). this.methodName = function() {}

C). function methodName() {}

D). methodName: function() {}

How do you add a method to an object created with a constructor function?

A). this.methodName = function() {}

B). this.methodName: function() {}

C). this.methodName = () {}

D). this.methodName: () {}