Javascript from scratch

Declare JavaScript variables with let, var, and const. Compare their reassignment rules and scope, noting that let is block-scoped, var is older, and const cannot be reassigned.

Explore data types in JavaScript, distinguishing primitive types from reference types, and learn hands-on with string and number using let, console.log, and typeof.

Explore JavaScript data types including BigInt, boolean, undefined, null, and symbol, and master assignment, arithmetic, and comparison operators.

Learn how to use if-else statements in JavaScript to implement logic with conditions, braces, else if, and age thresholds like 18 and 70.

Explore loops in JavaScript with the for loop to repeat code and iterate arrays from index zero to length. Understand while and do while loops and avoid infinite loops.

Learn how to declare and call functions in JavaScript, create reusable blocks of code with parameters and return values, and see how functions improve organization and maintainability.

Explore how to declare and call JavaScript functions using the function keyword, pass parameters, and return values. See examples with console.log, arguments, and dynamic behavior.

Understand scope in JavaScript, including global scope accessible everywhere and local scope inside functions, to write safer code and avoid bugs.

Explore the document object model and learn how JavaScript manipulates a live page map to select elements, modify text, and create interactive web content.

Learn to select elements from the document object model using id, class, and tag selectors with getElementById, querySelector, and querySelectorAll, then modify content and style, including a button example.

Learn to build interactive websites by listening for user events with JavaScript and addEventListener, such as click and input, updating content in real time with innerText and style changes.