How can you check if the age property exists in the person object?
A). 'age' in person
B). person.has('age')
C). person.contains('age')
D). person.hasOwnProperty('age')
What is the purpose of the this keyword in a constructor function?
A). It refers to the new object being created.
B). It refers to the global object.
C). It refers to the current object.
D). It refers to the parent object.
How do you define a constructor function for creating Car objects?
A). function Car(make, model) { this.make = make; this.model = model; }
B). Car(make, model) { this.make = make; this.model = model; }
C). var Car = function(make, model) { this.make = make; this.model = model; };
D). Car = function(make, model) { this.make = make; this.model = model; };
What is the correct way to create an object in JavaScript?
A). var obj = {};
B). var obj = [];
C). var obj = ();
D). var obj = <>;
What does Object.keys(person) return if var person = {name: 'John', age: 30};?
A). ['name', 'age']
B). ['John', 30]
C). {'name', 'age'}
D). {'John', 30}
How do you access the value of the name property in the object var person = {name: 'John', age: 30};?
A). person['name']
B). person.name
C). person->name
D). person::name
What will console.log(car.make); output if var car = {make: 'Toyota', model: 'Corolla'};?
A). Toyota
B). Corolla
C). Undefined
D). Error
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 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 {}
What is the output of console.log(person.greet()); if var person = {greet: function() {return 'Hello';}};?
A). Hello
B). Undefined
C). Error
D). Hello