Crazycoders Lab

Python is one of the most in-demand programming languages in the world, and with good reason. It's powerful, versatile, and easy to learn. If you're interested in learning Python, then you're in luck! CrazyCodersLab has just launched a new Python programming course for beginners.

In this course, you'll learn everything you need to know to get started with Python, from the basics of variables and data types to more advanced concepts like object-oriented programming and machine learning. And the best part is, you don't need any prior programming experience to get started!

Here are just a few of the things you'll learn in this course:

What Python is and why it's so popular
The basics of Python syntax, variables, and data types
Conditional statements and loops
Functions and classes
Object-oriented programming
File I/O
Regular expressions
Databases
Machine learning
And much more!

This course is perfect for anyone who wants to learn Python, whether you're a complete beginner or you have some prior programming experience. And because it's taught by experienced and passionate instructors, you can be sure that you'll be learning from the best.

So what are you waiting for? subscribe for CrazyCodersLab's new Python programming course today and start your journey to becoming a Python developer!

Subscribe for CrazyCodersLab's new Python programming course today and start your journey to becoming a Python developer! Click the link below to learn more:

youtube.com/@crazycoderslab

2 years ago (edited) | [YT] | 2

Crazycoders Lab

Node.js Basics

Q. What is Node.js Process Model?
Answer: Node.js runs in a single process and the application code runs in a single thread and thereby needs less resources than other platforms.

All the user requests to your web application will be handled by a single thread and all the I/O work or long running job is performed asynchronously for a particular request. So, this single thread doesn't have to wait for the request to complete and is free to handle the next request. When asynchronous I/O work completes then it processes the request further and sends the response.

Q. What are the key features of Node.js?
Answer: Asynchronous and Event driven – All APIs of Node.js are asynchronous. This feature means that if a Node receives a request for some Input/Output operation, it will execute that operation in the background and continue with the processing of other requests. Thus it will not wait for the response from the previous requests.

Fast in Code execution – Node.js uses the V8 JavaScript Runtime engine, the one which is used by Google Chrome. Node has a wrapper over the JavaScript engine which makes the runtime engine much faster and hence processing of requests within Node.js also become faster.

Single Threaded but Highly Scalable – Node.js uses a single thread model for event looping. The response from these events may or may not reach the server immediately. However, this does not block other operations. Thus making Node.js highly scalable. Traditional servers create limited threads to handle requests while Node.js creates a single thread that provides service to much larger numbers of such requests.

Node.js library uses JavaScript – This is another important aspect of Node.js from the developer's point of view. The majority of developers are already well-versed in JavaScript. Hence, development in Node.js becomes easier for a developer who knows JavaScript.

There is an Active and vibrant community for the Node.js framework – The active community always keeps the framework updated with the latest trends in the web development.

No Buffering – Node.js applications never buffer any data. They simply output the data in chunks.

Q. How does Node.js work?
Answer: A Node.js application creates a single thread on its invocation. Whenever Node.js receives a request, it first completes its processing before moving on to the next request.

Node.js works asynchronously by using the event loop and callback functions, to handle multiple requests coming in parallel. An Event Loop is a functionality which handles and processes all your external events and just converts them to a callback function. It invokes all the event handlers at a proper time. Thus, lots of work is done on the back-end, while processing a single request, so that the new incoming request doesn't have to wait if the processing is not complete.

While processing a request, Node.js attaches a callback function to it and moves it to the back-end. Now, whenever its response is ready, an event is called which triggers the associated callback function to send this response.

Q. What is difference between process and threads in Node.js?
Answer: 1. Process:

Processes are basically the programs that are dispatched from the ready state and are scheduled in the CPU for execution. PCB (Process Control Block) holds the concept of process. A process can create other processes which are known as Child Processes. The process takes more time to terminate and it is isolated means it does not share the memory with any other process.

The process can have the following states new, ready, running, waiting, terminated, and suspended.

2. Thread:

Thread is the segment of a process which means a process can have multiple threads and these multiple threads are contained within a process. A thread has three states: Running, Ready, and Blocked.

The thread takes less time to terminate as compared to the process but unlike the process, threads do not isolate.

Q. How to create a simple server in Node.js that returns Hello World?
Answer:
Step 01: Create a project directory

mkdir myapp
cd myapp
Step 02: Initialize project and link it to npm

npm init
This creates a package.json file in your myapp folder. The file contains references for all npm packages you have downloaded to your project. The command will prompt you to enter a number of things. You can enter your way through all of them EXCEPT this one:

entry point: (index.js)
Rename this to:

app.js
Step 03: Install Express in the myapp directory

npm install express --save
Step 04: app.js

/**
* Express.js
*/
const express = require('express');
const app = express();

app.get('/', function (req, res) {
res.send('Hello World!');
});

app.listen(3000, function () {
console.log('App listening on port 3000!');
});
Step 05: Run the app

node app.js

Q. Explain the concept of URL module in Node.js?
Answer: The URL module in Node.js splits up a web address into readable parts. Use require() to include the module. Then parse an address with the url.parse() method, and it will return a URL object with each part of the address as properties.

Example:

/**
* URL Module in Node.js
*/
const url = require('url');
const adr = 'http://localhost:8080/default.htm?year=2022&month=september';
const q = url.parse(adr, true);

console.log(q.host); // localhost:8080
console.log(q.pathname); // "/default.htm"
console.log(q.search); // "?year=2022&month=september"

const qdata = q.query; // { year: 2022, month: 'september' }
console.log(qdata.month); // "september"

Q. What are the data types in Node.js?
Answer:
Just like JS, there are two categories of data types in Node: Primitives and Objects.



1. Primitives:

String
Number
BigInt
Boolean
Undefined
Null
Symbol


2. Objects:

Function
Array
Buffer

2 years ago | [YT] | 3

Crazycoders Lab

2 years ago | [YT] | 4

Crazycoders Lab

Which of the following is true about EventEmitter.emit property?

2 years ago | [YT] | 3

Crazycoders Lab

Which of the following command will show version of Node?

2 years ago | [YT] | 4

Crazycoders Lab

Help Us Decide the Core or Framework for Our Live Project!

We value your input! We're about to start a new live project, and we need your help in choosing the right framework. Should we continue with Core PHP or switch to Laravel? Cast your vote and let us know your thoughts in the comments!

2 years ago | [YT] | 3

Crazycoders Lab

1000 subscribers! This is such an amazing feeling. Thank you to everyone who has subscribed to my channel and supported my work. I'm so excited to keep creating content and sharing it with you all. I can't wait to see what the future holds for my channel.

2 years ago | [YT] | 3

Crazycoders Lab

<?php
$a = 10;
$b = 20;

function swap(&$x, &$y) {
$temp = $x;
$x = $y;
$y = $temp;
}

swap($a, $b);

echo "a: " . $a . ", b: " . $b;
?>

2 years ago | [YT] | 3

Crazycoders Lab

**Join Our Live Free PHP & Node.js Class in Hindi!** 🚀🎉



🌟 **Attention, all coding enthusiasts!** 🌟



Are you eager to learn PHP & Node.js programming languages? Look no further! We are thrilled to announce the launch of our **live and interactive** coding classes in **Hindi**!



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In this comprehensive course, you will dive into the world of PHP & Node.js, two of the most powerful and widely-used languages for web development. Whether you're a complete beginner or already have some programming experience, our classes are tailored to suit all skill levels.



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5. **Community & Support:** Join a supportive community of learners, where you can ask questions, share insights, and grow together.



🌐 **How to Join:**



Simply head over to our YouTube channel at **youtube.com/@crazylearners4855** and hit the **"Subscribe"** button. Don't forget to turn on the notification bell, so you never miss a class!



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Don't miss this fantastic opportunity to master PHP & Node.js in Hindi. Sharpen your coding skills, unlock new possibilities, and embark on an exciting coding journey with us!



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2 years ago | [YT] | 0