Explore the basics of JavaScript in greater detail to solve real-world problems.

Zero to Hero in JavaScript

This module aims to teach us how to write cleaner, more modular, and more scalable code in JavaScript by giving us an understanding of object-oriented programming (OOP). We'll start with the basics of object-oriented programming and build up to more advanced concepts such as data protection and inheritance. Along the way, we'll learn how each concept applies to JavaScript in particular, as well as how various JavaScript features make it a suitable language for object-oriented programming.

JavaScript: A Deep Dive

In this lesson, we explore ways of writing nested functions.


# Introduction to nested functions
We call **functions** ***nested*** when some function is *declared* inside another function.
## Writing nested functions
The process to write **nested functions** is straightforward. We declare a function *inside* another function. Take a look at the following example.

function outer (a){ // This is the outer function
  console.log("Outer function executed with arg",a);
  function inner(b){ // This is the inner function 
    console.log("Inner function executed with arg:",b);
    return; // Exit inner function
  }
  inner(a); // Call inner function declared above 
  return; // Exit outer function
}
outer(1); // Call outer function declared above

In the code above, we declare two functions -- `outer` and `inner`. We declared the function `inner` inside the function `outer`. When we call the `outer` function in **line 10**, it executes and declares an entire function called `inner`. It then calls the `inner` function on **line 7**, while giving the same passed argument `a`.


The order of print statements shows the order in which the functions are *executed*.



Introduction to nested functions in JavaScript.


Nested Functions in JavaScript

Introduction to nested functions

Writing nested functions