Node.js Course Introduction and JavaScript Basics

Introduction

• Objective: Learn Node.js - a popular server-side environment for JavaScript.
• Course Provider: Kayla
• Instructor: Developer Advocate with Scalar.
• Course Structure: From scratch to advanced Node.js topics.

Understanding JavaScript Basics

• Importance: Node.js runs JavaScript code on your machine (runtime environment).
• Language: JavaScript is core; Node.js built on C++ but supports JavaScript.

JavaScript Essentials

• Variables: Declaring and initializing variables in JavaScript.
• Arrays: Creating and manipulating arrays.
• Objects: Understanding and utilizing JavaScript objects.
• Functions: Creating and invoking functions.
• Scoping: Difference between var, let, and const.

Scoping in JavaScript

• Keywords: var, let, const.
  • var is function-scoped, can be redeclared and reassigned.
  • let is block-scoped, can be reassigned but not redeclared.
  • const is block-scoped, cannot be reassigned or redeclared.
• Types of Scoping: Block scoping and function scoping.

Setting Up Node.js

• Installation: Steps to install Node.js on Windows, Mac, and Linux.
• Verification: Using the command prompt to validate installation.
• Running JavaScript: Using Node.js to run JavaScript files on the local machine.
• Environments: Browsers and local machines using Node.js runtime.

Running JavaScript in Browser

• DevTools Console: Using the console.log method to print messages.
• Creating HTML and JS Files:
  • Link JavaScript file (demo.js) to HTML (index.html).
  • Use the script tag to include JavaScript in HTML.

Running JavaScript with Node.js

• Node.js Command: node <filename.js> to execute JavaScript files.
• Terminal: Use integrated terminal in IDE for running Node.js scripts.

JavaScript Fundamentals

Variables

• Definition: Used to store values for future use.
• Declaration: Using var, let, and const.
• Dynamic Typing: JavaScript variables are dynamically typed.
• Example: Integer, string, boolean assignments.
• Differences:
  • var: Redeclaration and reassignment allowed.
  • let: Reassignment allowed, redeclaration not allowed.
  • const: Neither reassignment nor redeclaration allowed.

Arrays

• Definition: Data structure to store multiple values.
• Initialization: Square brackets ([ ]) with values separated by commas.
• Indexing: Starts at 0.
• Accessing Elements: Using indices (array[index]).
• Dynamic Nature: Arrays can hold mixed data types.
• Methods:
  • push(): Adds element to end.
  • pop(): Removes element from end.
  • unshift(): Adds element to start.
  • shift(): Removes element from start.

Objects

• Definition: Collection of data in key-value pairs.
• Initialization: Curly braces ({}) with key-value pairs.
• Key Types: Strings, numbers, booleans, arrays, other objects.
• Accessing Values:
  • Dot notation (object.key).
  • Bracket notation (object['key']).
• Modifying Objects:
  • Adding properties.
  • Deleting properties using delete keyword.
  • Updating properties.

Functions

• Definition: A block of code designed to perform a particular task.
• Declaration: Using function keyword.
• Parameters and Arguments:
  • Parameters: Variables listed as part of the function definition.
  • Arguments: Values passed to the function.
• Invocation: Calling the function (functionName()).
• Types of Functions:
  • Regular functions.
  • Function expressions (functions as variables).
  • Immediately Invoked Function Expressions (IIFE).

Conclusion

• Learning Path: This foundational knowledge of JavaScript is essential for advancing in Node.js.
• Next Steps: Upcoming videos will cover more advanced concepts and topics.
• Engagement: Subscribe for more content and updates.