How can you check if a property exists in an object?

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

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 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.

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 define a class in JavaScript ES6?

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

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

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

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

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 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 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

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);