Q
How do you define a method named greet in an object var person = {};?

Answer & Solution

Answer: Option A
Solution:
Methods in objects are defined as properties with function values: person.greet = function() {};.
Related Questions on Average

How do you iterate over all properties of an object var person = {name: 'John', age: 30};?

A). for (var key in person)

B). for (var key of person)

C). forEach(key in person)

D). forEach(key of person)

What is the output of console.log(person.greet()); if var person = {greet: function() {return 'Hello';}};?

A). Hello

B). Undefined

C). Error

D). Hello

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; };

How do you add a method to an object created with a constructor function?

A). this.methodName = function() {}

B). this.methodName: function() {}

C). this.methodName = () {}

D). this.methodName: () {}

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 will the following code output? console.log(person['age']); if var person = {name: 'John'};

A). 30

B). John

C). undefined

D). null

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

How can you delete the age property from the person object?

A). delete person.age;

B). remove person.age;

C). person.age = null;

D). person.age.delete;

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()