Beginner’s Javascript Course Notes

Introduction

• Instructor: Beau Carnes from freeCodeCamp.org
• Course Purpose: To teach beginners everything about Javascript and provide a refresher on basic Javascript syntax.
• Standalone Video: Can be used without the freeCodeCamp.org curriculum, but might be beneficial to use alongside it.
• Project Building: Encouragement to build personal projects after coursework to enhance learning.

Setting Up Javascript

• Installation: Javascript does not require installation as it's supported by all web browsers.
• Code Editors: Recommendations include Sublime Text, Visual Studio Code, Atom.
• Using HTML: Creating an HTML file with <script> tags to write Javascript.
• Console.log: Use in the console to display output (e.g., console.log("Hello World")).

Options for Writing Javascript

1. freeCodeCamp Code Editor: Built-in editor with a console.
2. CodePen: Online IDE for HTML, CSS, and Javascript with separate windows for each language.
3. Scrimba: A tool used for recording the course, offering a unique console experience.

Comments in Javascript

• Single-line Comments: Use // for inline comments.
• Multi-line Comments: Use /* comment */ format.

Data Types and Variables

• Data Types:
  • Undefined, Null, Boolean (true/false), String, Symbol, Number, Object.
• Declaring Variables:
  • var, let, const.
  • var has function scope, let has block scope, const cannot be reassigned.

Assigning Values

• Assignment Operator: Uses = to assign a value to a variable, e.g., var a = 7;
• Using console.log: To debug and print variable values.

Arithmetic Operations

• Basic Operations: Addition +, Subtraction -, Multiplication *, Division /, Increment ++, Decrement --.
• Remainder Operator: % finds the remainder of a division.

Arrays and Their Properties

• Defining an Array: var myArray = [1, 2, 3];
• Accessing Elements: Use indexes (0-based)
• Modifying Arrays: Use methods like push(), pop(), shift(), unshift().
• Nested Arrays: Arrays within arrays, can be accessed using multiple indexes.

Functions and Scope

• Function Declaration: Use the function keyword followed by parameters.
• Return Statement: Use return to send a value back from a function.
• Global vs Local Scope: Variables defined outside functions are globally scoped, while those inside are locally scoped.
• Arrow Functions: A concise way to write functions with the => syntax.

Objects in Javascript

• Creating Objects: Use curly braces {} to define key-value pairs.
• Accessing Properties: Use dot notation (e.g., object.property) or bracket notation (e.g., object['property']).
• Adding/Deleting Properties: You can manipulate object properties using delete keyword.

ES6 Features

• Destructuring Assignment: Simplifies extracting values from arrays/objects.
• Template Literals: Allows embedding expressions in strings using backticks ``.
• Modules: Use import and export to share code across files.

Conclusion

• Encouragement to practice and create personal projects.
• Reminder to subscribe to freeCodeCamp for more resources and learning opportunities.