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Node.js Callbacks

Introduction to Node.js
What is Node.js? History and Evolution of Node.js Advantages and Disadvantages of Node.js Use Cases of Node.js
Setting Up Node.js Environment
Node.js Installation Configuring Node.js NPM (Node Package Manager) Basic NPM Commands
Node.js Fundamentals
Node.js Architecture Node.js Modules Node.js Globals Node.js Callbacks EventDriven Programming Asynchronous Programming Streams and Buffers
Working with Node.js Modules
Creating and Exporting Modules Builtin Modules NPM Modules Creating a Package.json file Working with Module Dependencies Understanding Semantic Versioning
Express.js
Introduction to Express.js Setting Up Express.js HTTP Request Methods Routing in Express.js Request and Response Objects Middlewares in Express.js Handling Errors in Express.js
Working with Databases in Node.js
Introduction to Databases SQL vs NoSQL Databases Connecting to Databases in Node.js MongoDB (a NoSQL Database) Mongoose (an Object Data Modeling Library) CRUD Operations with MongoDB and Mongoose
Testing and Debugging in Node.js
Why is Testing Important? Unit Testing Integration Testing Debugging Node.js Applications Debugging with npm Debugger Debugging with Visual Studio Code
Deployment and Scaling of Node.js Applications
Deploying Node.js Applications Understanding the Different Environments Clustering in Node.js Load Balancing in Node.js Process Management in Node.js
Security in Node.js Applications
Common Security Threats Web Application Security Secure Coding Practices Authentication and Authorization Handling Passwords and Sensitive Data
Best Practices and Patterns in Node.js
Coding Best Practices Design Patterns Architectural Patterns Scalable Application Architecture Choosing the Right Tools and Techniques

Node.js Callbacks

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#description

Node.js is an event-driven, non-blocking I/O model that is designed to be scalable and efficient. One of the key features of Node.js is its use of callbacks, which allow for asynchronous and non-blocking processing.

Callbacks are functions that are passed as arguments to other functions, and are executed when the parent function has finished its processing. This allows for asynchronous processing, as the parent function can continue executing while waiting for the callback to complete.

In simple terms, callbacks allow Node.js to handle multiple requests simultaneously, without the need for additional threads or processes. They are an essential part of Node.js programming, and are used extensively in creating scalable and efficient web applications.

Here is an example of a callback function:

 
                    
function addNumbers(a, b, callback) {
  let sum = a + b;
  callback(sum);
}

In this example, the function addNumbers takes two arguments a and b, and a callback function. The function calculates the sum of a and b, and then passes the result to the callback function.

To call this function and handle the result using a callback, you would use code like this:

 
                    
addNumbers(2, 3, function(result) {
  console.log(result);
});

This code passes the values of 2 and 3 as arguments to the addNumbers function, and defines a callback function that handles the result. When the addNumbers function completes, it executes the callback function, passing in the result of the calculation. The result is then printed to the console using console.log.

Overall, using callbacks is a fundamental concept in Node.js programming, and is essential for creating scalable and efficient applications.

March 25, 2023

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