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)
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
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);
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 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; }
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')
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
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');
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 the output of car.start() if var car = {start: function() {console.log('Car started');}};?
A). Car
B). started
C). Car started
D). Error