What is the purpose of the this keyword in an object method?

What does Object.keys(obj) return?

A). An array of the values of the object's properties

B). An array of the names of the object's properties

C). The first key of the object

D). The number of properties in the object

What is encapsulation in the context of JavaScript objects?

A). Hiding the internal state and requiring all interaction to be performed through an object's methods

B). Extending one object from another

C). Creating a new object

D). Removing a property from an object

What is the output of car.start() if var car = {start: function() {console.log('Car started');}};?

A). Car

B). started

C). Car started

D). Error

What will car['make'] return if var car = {make: 'Ford', model: 'Mustang'};?

A). Ford

B). Mustang

C). Undefined

D). Error

What does Object.assign(target, ...sources) do?

A). Copies properties from sources to target

B). Compares properties between target and sources

C). Deletes properties in sources

D). Merges properties of sources into target and removes duplicates

How do you define a method in a constructor function?

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

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

C). this.methodName = () {}

D). this.methodName: () {}

Which method can be used to call a function defined within an object?

A). object.functionName();

B). object->functionName();

C). object::functionName();

D). object.callFunction('functionName');

Which of the following is a correct way to define an object using an object literal?

A). var car = {make: 'Toyota', model: 'Corolla'};

B). var car = make: 'Toyota', model: 'Corolla';

C). var car = new Object(make: 'Toyota', model: 'Corolla');

D). var car = Object.create(make: 'Toyota', model: 'Corolla');

Which of the following correctly creates an instance of a Car object using a constructor function?

A). var myCar = Car('Toyota', 'Corolla', 2020);

B). var myCar = new Car('Toyota', 'Corolla', 2020);

C). var myCar = create Car('Toyota', 'Corolla', 2020);

D). var myCar = construct Car('Toyota', 'Corolla', 2020);

How can you iterate over all properties of an object?

A). for (var key of object)

B). for (var key in object)

C). for (var key with object)

D). for (var key over object)