Go through the fundamentals of JavaScript that interviewers expect you to know, and get plenty of practice along the way.

Ace the Front End Interview

Don't Skip JavaScript

### Explanation

Run the code from the question below:

function Add(){
    console.log(answer)
    var answer = 2
};
Add()

The above code displays `undefined` as an answer due to the concept of *hoisting* in Javascript.

### Hoisting

In JavaScript, a variable can be declared after it has been used. This is because variable declarations using `var` are *hoisted* to the top of their functional scope at compile time. Hence, a variable can be initialized and used before it has been declared.

Let's take a look at an example:



## Explanation

Run the code from the question below:

The above code displays `undefined` as an answer due to the concept of *hoisting* in Javascript.

## Hoisting

In JavaScript, a variable can be declared after it has been used. This is because variable declarations using `var` are *hoisted* to the top of their functional scope at compile time. Hence, a variable can be initialized and used before it has been declared.

Let's take a look at an example:



In this lesson, we will discuss the solutions to the questions in the previous lesson.


Basics

Event Handling

Asynchronus Callbacks

OOP in JavaScript

Security

Don’t Bomb The DOM

Solution review: Hoisting

Question 1: Solution review #

Explanation #

Hoisting