Top 5 Javascript ES6 Interview Questions and Answers

JavaScript is one of the most popular programming languages today, and its latest version, ES6 (also known as ECMAScript 2015), has introduced many new features that have greatly improved the language. As a result, many companies now require candidates to have a good understanding of ES6 in order to qualify for JavaScript developer positions. In this blog post, we will cover some of the most common ES6 interview questions and answers that you should know.

What are some of the new features introduced in ES6?

ES6 introduced many new features, including:

1. Arrow functions
2. Template literals
3. Classes
4. Let and const
5. Destructuring
6. Default parameters
7. Rest and spread operators

What is an arrow function, and how is it different from a regular function?

An arrow function is a shorthand way of writing a function in JavaScript. It is different from a regular function in that it does not have its own this value, which means it always refers to the this value of its surrounding context. It also has a shorter syntax and automatically returns the result of its expression.

What are template literals, and how do you use them?

Template literals are a new way of writing strings in JavaScript. They allow you to include expressions within a string by enclosing them in ${}. For example:

const name = "John";
console.log(`Hello, ${name}!`);

This will output Hello, John! to the console.

What are classes, and how do you use them?

Classes are a new way of defining objects in JavaScript. They provide a cleaner syntax for creating object blueprints and allow for easy inheritance. To define a class, you use the class keyword, followed by the name of the class, and the constructor method, which is called when an object is created. For example:

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  sayHello() {
    console.log(`Hello, my name is ${this.name} and I'm ${this.age} years old.`);
  }
}

const john = new Person("John", 30);
john.sayHello(); // Outputs "Hello, my name is John and I'm 30 years old."

What is the difference between let and const?

let and const are new ways of declaring variables in JavaScript. let declares a variable that can be reassigned, while const declares a variable that cannot be reassigned. For example:

let x = 1;
x = 2; // This is allowed

const y = 1;
y = 2; // This will result in an error