Javascript Lesson

Introduction to Javascript

• Introduction to JavaScript programming language (incomplete due to background noise).

Variables and Data Types

• Variables are essential in programming to store data and manipulate it.
• Key terms:
  • const - declares a constant variable.
  • let - declares a block-scoped local variable.
  • var - declares a function-scoped or globally-scoped variable.
• Data types in Javascript:
  • Number
  • String
  • Boolean
  • Object
  • Undefined
  • Null

Operators

• Arithmetic operators:

  • + (addition)
  • - (subtraction)
  • * (multiplication)
  • / (division)
  • % (modulus)

• Assignment operators:

  • = (assignment)
  • += (addition assignment)

UI Elements in HTML

• Creating buttons in HTML using <input type="button">
• Example:

  <input type="button" value="Click me">
  

Arrays in Javascript

• Declaring arrays and adding elements.
  • Example: const animals = ['cat', 'dog', 'elephant'];
  • Accessing array elements using indices.
  • Array methods.

Inspecting Elements

• Right-clicking and selecting "Inspect" in the browser to open Developer Tools.

DOM Manipulation

• Selecting elements by ID using document.getElementById().
• Adding and manipulating elements.
• Example:

  let element = document.getElementById('myElement');
  element.innerText = 'Hello, world!';
  

Object-Oriented Programming (OOP) in Javascript

• Concepts of OOP:

  • Class
  • Object
  • Methods
  • Properties

• Example of a class in Javascript:

  class Employee {
      constructor(name, position, salary) {
          this.name = name;
          this.position = position;
          this.salary = salary;
      }
      getDetails() {
          return `${this.name} is a ${this.position} earning ${this.salary}`;
      }
  }