How do you add a method to an object created wit...

How do you get the number of properties in an obj...

A). Object.keys(book).length

B). book.countProperties()

C). book.totalProperties()

D). book.length()

How do you inherit properties and methods from a...

A). class SubClass extends SuperClas...

B). class SubClass inherits SuperCla...

C). class SubClass implements Super...

D). class SubClass derives SuperCla...

How do you define a method 'sayHello' in an obj...

A). person.sayHello = function() {};

B). person.sayHello: function() {};

C). person.sayHello = () {};

D). person.sayHello = function {};

How can you remove a property 'email' from an obj...

A). delete user.email;

B). user.remove('email');

C). user.email = null;

D). user.pop('email');

What is the purpose of the 'super' keyword in a ...

A). It calls methods from the paren...

B). It creates a new instance of the...

C). It refers to the current object.

D). It checks for property existence.

What is the correct way to create an empty object...

A). var obj = {};

B). var obj = ();

C). var obj = [];

D). var obj = <{}>;

How do you iterate over all properties of an obj...

A). for (var prop in person)

B). forEach(prop in person)

C). for (var prop of person)

D). forEach(prop of person)

How do you define a constructor function for crea...

A). function Car(make, model) { thi...

B). Car(make, model) { this.make = m...

C). var Car = function(make, model) ...

D). Car = function(make, model) { t...

How do you check if an object has a property 'col...

A). 'color' in obj

B). obj.hasProperty('color');

C). obj.contains('color');

D). obj.propertyExists('color');

What is the output of console.log(obj.prop) if ob...

A). It prints undefined.

B). It throws an error.

C). It prints null.

D). It prints true.