Introduction To JavaScript Call Stack
Tags: beginners, programming, javascript, tutorial
Published: 2023-03-14 14:53:24

## Introduction

Throughout the years, JavaScript has grown in popularity and now powers a significant chunk of the internet. The call stack, which is used to track function calls and their execution order, is one of the fundamental ideas of JavaScript.

Any JavaScript developer must understand the call stack in order to efficiently debug their code and create applications that are more streamlined.

In this post, we'll examine the fundamentals of the JavaScript call stack, as well as its use, operation, and some typical problems that could occur.

You will have a firm grasp of the call stack's definition and how to use it efficiently by the end of this article.

## What is a Stack?

A stack is a basic data structure in computer science. The last object placed on the stack goes on top, just like when you stack some things or pile up some books. It also starts to be taken away. the last stack is the first to be taken away.

The call stack works in the same way. A function is added to the call stack and afterwards removed from the call stack when a value is returned from the function.
     

![photo by https://www.slideteam.net/media/catalog/product/cache/1280x720/i/n/information_technology_stack_7_layers_diagram_Slide01.jpgphoto](https://paper-attachments.dropboxusercontent.com/s_3CE0A84A2FE0F3D3670025EAE044B34CB66BCB971F3EDEBB022ED29A1BCF12A2_1678719989548_Screenshot+Capture+-+2023-03-13+-+16-05-44.png)


 
    
When a program with numerous function calls starts, the first function that the interpreter reaches is added to the call stack. The function is then called, and if it calls another function, the latter function is added to the call stack's top position.

Up until one of the functions returns a value, this procedure keeps on. The function is then deleted from the call stack when this occurs. At the top of the call stack is the function that is now running (or being performed).

## What is a Call Stack in JavaScript?

A call stack is a mechanism used in JavaScript to keep track of function execution. A function is added to the top of the call stack whenever it is called. The function runs, and when it completes, the stack is cleared.

A call stack is a data structure that, at its most basic level, employs the Last In, First Out (LIFO) principle to organize and temporarily record function invocation (call).

This is a breakdown of what we mean:

When we say that the call stack runs according to the Last In, First Out (LIFO) data structure principle, we imply that the last function that is pushed into the stack is the first function that comes out when the function returns.

The execution of function calls in a program is tracked by this data structure. It records the functions that are now active as well as the order in which they were invoked. A function is called, added to the top of the call stack, and then removed when it completes its work.

Let's take an example to illustrate this:

    function add(x, y) {
      return x + y;
    }
    
    function square(z) {
      return z * z;
    }
    
    function calculate(a, b, c) {
      const sum = add(a, b);
      const squaredSum = square(sum);
      return squaredSum / c;
    }
    
    calculate(2, 3, 4);

When the 'calculate' function is used, the following happens:

1. Adding 'compute' to the call stack.
2. The commands "add" and "3" are called. The word "add" is placed at the top of the call stack.
3. The call stack is cleared once the function "add" returns "5".
4. The word "square" is called with the parameter "5". Square gets added to the call stack's top.
5. The call stack is cleared after the function "square" returns "25".
6. From "calculate," the value of "square" is divided by "4" and returned.
7. The call stack is cleared of the word "compute".



So the call stack in this example would look like this:

       +-------------+
                    |   calculate |
                    +-------------+
                    |     add     |
                    +-------------+
                    |    square   |
                    +-------------+


This is a simplified example, but it illustrates the basic idea of how the call stack works.


## What is the purpose of JavaScript Call Stack?

The method used in JavaScript to track function calls in a program is called the call stack. The call stack's goals are to govern the flow of control between functions and make sure that function calls are executed in the proper sequence.

A new frame, corresponding to the function's execution context, is added to the call stack each time a function is called in JavaScript. The frame holds details about the function, such as its local variables and parameters. The function may call additional functions as it runs, which increases the call stack by adding new frames.

The call stack is in charge of recording the calling sequence of functions and ensuring that they are executed in the proper order. Control is transferred back to the function that called the other function after the execution of a function is complete.

An essential idea in JavaScript is the call stack, which is crucial to the way programs are run. It is imperative for developers to have a thorough understanding of the call stack in order to produce effective, error-free code.

****
## **Some Common Issues That Can Arise When Working With JavaScript Call Stack.**

The call stack is an essential part of the JavaScript runtime environment, but using it frequently can lead to a number of typical problems. Many of the most typical call stack-related difficulties are listed below:


1. Maximum call stack size exceeded: When a recursive function or an endless loop repeatedly calls itself, the call stack's maximum size is exceeded, resulting in this error. The software may crash due to this problem, which is frequently challenging to troubleshoot.


2. Stack overflow: When there is not enough room on the call stack to store a new frame, a stack overflow error happens. When a function is called repeatedly without an exit condition, the call stack might get bloated.


3. Callback hell: When a program uses numerous nested callbacks, it enters callback hell, making the code challenging to read and debug. Working with callback-required APIs or asynchronous code may cause this to occur.


4. Synchronous code blocking: JavaScript executes code synchronously, which necessitates the completion of one function call before executing the next. The call stack may become blocked by a function that takes a while to run, rendering the program unresponsive.




## Conclusion

I hope you gained a lot from this topic. we were able to look at JavaScript call stack. what it is,       how   it works and some common issues you can encounter when working with it. if you have         questions or  comments. Feel free to drop it. Bye, I will see in the next one.
 


## About the Author

I am Jennifer Eze, an enthusiastic developer with a passion for JavaScript, Bootstrap, PHP, HTML & CSS.
I work as a freelancer, building websites for clients, and love writing technical tutorials to teach others what I do. I am eager to hear from you. Reach me on [LinkedIn](https://www.linkedin.com/in/jennifer-eze-969272239/), [GitHubitHub](https://github.com/nnekajenny), or my [website](https://nnekajenny.github.io/).