What does Object.keys(obj) return?

How do you add a new property to an existing object in JavaScript?

A). object.property = value;

B). object->property = value;

C). object:property = value;

D). object.addProperty('property', value);

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

A). Ford

B). Mustang

C). Undefined

D). Error

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

A). It refers to the global object.

B). It refers to the current object.

C). It refers to the parent object.

D). It refers to the previous object.

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 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 can you check if a property exists in an object?

A). 'property' in object

B). object.hasProperty('property')

C). object.contains('property')

D). object.includes('property')

How do you define a constructor function for a Car object?

A). function Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

B). Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

C). function create Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

D). function construct Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

What will the following code output? console.log(car.make); if var car = {make: 'Honda', model: 'Civic'};

A). Honda

B). Civic

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

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