Building Websites JavaScript and the DOM

Explore building dynamic, interactive web pages with javascript by mastering variables, data types, arrays, objects, functions, the document object model, and event listeners.

Learn how to add JavaScript to web pages, create interactive elements with the DOM, and view real-time effects using code pen and brackets.

Learn how to create and run JavaScript in the browser — an interpreted language that requires no compiling — using .js files, script tags, and external scripts for reusable, easier maintenance.

Learn where to place JavaScript on a page (top or bottom) and how the DOM renders HTML, then use dev tools and console for debugging, with comments, semicolons, and whitespace.

Explore arrays and objects in JavaScript by storing multiple values in a single variable, accessing items by index or property name, and using dynamic bracket notation and dot notation.

Explore working with arrays and objects in JavaScript, updating and outputting dynamic values, and using array methods like push to grow the array while distinguishing array indices from object keys.

Explore array manipulation in JavaScript by pushing and popping to add or remove items, updating the first value, and using splice, slice, sort, and reverse to shape data.

Explore functions in JavaScript, defining named blocks with the function keyword, passing arguments, and returning values. Learn how scope, global scope, and local scope drive dynamic, reusable code.

Explore how local and global scope affect variables inside and outside functions, including how global x and local b interact, and how function return values determine outputs.

Explore JavaScript operators from arithmetic and increment/decrement to comparison and ternary conditionals, and see how equality, type checks, and logical operators drive conditional logic in building websites with the DOM.

Learn how switch statements in JavaScript evaluate an expression against multiple cases, use breaks to stop execution, and include default and console logging to verify numeric and string results.

Explore how loops in JavaScript run code while a condition is true, using while, do-while, and the for loop, with x and a increments and console.log outputs.

Learn to use for loops to iterate arrays and objects, starting at index zero with length checks, and access object properties by key to output values.