Call Stack, Callback Queue, and Event Loop

The video tutorial explores the internals of Node.js and the V8 engine to understand asynchronous script execution. It explains the call stack, node APIs, callback queue, and event loop, using examples to illustrate synchronous and asynchronous execution. The tutorial aims to provide a mental model of how Node.js handles asynchronous operations, emphasizing the non-blocking nature of Node.js and the role of the event loop in managing callbacks.

What is the primary goal of the video tutorial?

• To learn about synchronous programming in JavaScript

• To explore the internals of Node.js and V8 for asynchronous script execution

• To understand how to build a weather application

• To learn about the history of JavaScript

What is the main function of the call stack in JavaScript?

• To handle errors

• To track the execution of functions

• To manage asynchronous events

• To store variables

In the call stack analogy, what does a can of tennis balls represent?

• A collection of error messages

• A queue of asynchronous events

• A list of variables

• A stack of function calls

What happens when a function is called in JavaScript?

• It is stored in a variable

• It is ignored

• It is added to the call stack

• It is removed from the call stack

In the complex synchronous example, what is the role of the 'forEach' method?

• To add items to an array

• To loop through each location and print it

• To remove items from an array

• To sort the array

What is the purpose of the event loop in Node.js?

• To handle errors

• To run items from the callback queue when the call stack is empty

• To manage the call stack

• To execute synchronous code

Why does Node.js allow non-blocking execution?

• Because it runs on a single core

• Because it does not support asynchronous programming

• Because it uses other threads in C to manage events

• Because it uses multiple threads for JavaScript code

What happens when the call stack is empty in an asynchronous program?

• The call stack is refilled with functions

• The program ends

• The event loop runs items from the callback queue

• The program crashes

What is the role of Node.js APIs in asynchronous programming?

• To handle errors

• To provide implementations for asynchronous functions like setTimeout

• To execute synchronous code

• To store variables

Why do asynchronous callbacks not run before the main function is done?

• Because they are stored in a different memory space

• Because the event loop waits for the call stack to be empty

• Because they are not important

• Because they are executed first