The Comple JavaScript From Beginner To Advanced

Learn how to declare and use JavaScript variables, assign values with the equals sign, and output them with console.log. Avoid reserved keywords, spaces in names, and starting with a number.

Explore strings, numbers, and booleans in JavaScript, using variables and if statements to control flow and practice console logging.

Explore how to work with arrays in JavaScript by building a list of items, using square brackets, zero-based indexing, and accessing elements and length.

Explore undefined and NaN in JavaScript by inspecting arrays, accessing missing indices, and using isNaN to distinguish not a number from strings or numbers.

Explore JavaScript objects by creating a user object with keys and values, access properties using dot notation, and compare objects with arrays to store structured data.

Learn JavaScript basics and the if statement to evaluate conditions and execute code, with examples using usernames and last names.

Learn how to extend if statements with else branches and not conditions to check usernames, compare to James, and trigger console logs or page reloads.

Master the switch control structure in JavaScript with cases, break, and default to map slot numbers to prizes, as shown through a wheel of fortune example contrasted with if statements.

Explore the for loop in JavaScript, setting a starting point and ending condition, iterating with x++ and nesting loops to run code multiple times.

Learn to control a for loop with break and continue. Use an if statement to stop the loop when a condition is met or skip iterations.

Practice iterating over arrays with a for loop, logging each element by index and using array.length to handle dynamic sizes.

Explore how the while loop works in JavaScript, including initialization, condition checks, and incrementing to print values from 2 to 5, with a comparison to the for loop.

Explore the addition operator in JavaScript with numeric and string examples, calculating totals from previous and current balances via console log, and decide between concatenation and addition.

Learn how the subtraction operator works with numbers, seeing the total update to 100, and understand why strings cannot be subtracted.

Explore the multiply operator in JavaScript, multiplying totals from previous and current values using the star symbol, and learn how decimals can require rounding and helpers.

Explains how the division operator computes totals in JavaScript with simple examples, prints results, and previews the upcoming discussion on equality operators two equals and three equals.

Learn how the comparison operators work in JavaScript, comparing numbers and strings with == and ===, and using != and !== in conditional statements.

Showcase JavaScript comparison operators, including greater than, less than, and their equals variants, through simple code and console.log checks; practice evaluating numbers like 1, 2, and 3.

Explore boolean operators in JavaScript by checking conditions like one equals one and one greater than five, showing how and requires all true while or needs only one true.

Learn how the ternary operator in JavaScript replaces an if statement with a one-line expression, using x and y comparisons to produce true, false, or equal and not equal results.

Learn to create and invoke a JavaScript function with the function keyword, a name, parentheses, and curly braces, using login and alert examples.

Explore how arguments pass data into a function and are received in order, with multiple arguments and meaningful names demonstrated in a login example.

Explore global and local scopes in JavaScript, showing how variables reside in the window global scope or inside a function's local scope, and how access via console logs works.

Learn how a function processes data and returns a value using the return keyword, illustrated by adding two arguments to produce five plus five equals ten.

Learn how JavaScript uses the window and the document object model to interact with the screen, inspect window properties, read location data, and manipulate the dom.

Explore the document object model to access and modify page content, including the title, body text, first element, and selecting elements for styling, such as turning color red.

Explore three DOM selection methods, from old to the modern querySelector, and learn to select by tag name, class name, and id.

Create and manipulate a new element by using a create method to produce a div, assign text, modify its style (color and font size), and insert it into the document.

Learn to insert a new element into the document by selecting a parent, creating a child, and using insert before or adjacent methods with beforebegin, afterbegin, beforeend, and afterend.

Learn to delete elements by targeting the parent and removing a UL element with removeChild, or use the simpler remove method.

Explore how JavaScript handles user events like click, mouseover, and double click, and learn why inline onclick can overwrite handlers and how to attach multiple events safely.

Master event listeners in JavaScript by attaching multiple functions to a single click, removing listeners, and handling page-wide click events to show pop-ups.

Explore how event propagation and bubbling work in the document, and learn to use the event object to access the target and modify styles.

Learn JavaScript arrays by creating arrays with square brackets, accessing and changing elements using 0-based indices, and adding values while exploring array length and sparse gaps.

Master array management in JavaScript by adding and removing elements with push, pop, shift, and unshift, then explore splice and slice in subsequent lessons.

Merge two arrays using concat, then convert to a string with join, and explore splitting and joining with custom separators to format data such as urls.

Explore indexOf to locate elements in an array and return -1 when not found. Compare slice and splice: slice returns a new array; splice mutates the original.

Use the array filter helper to create a new array by testing each item with a callback, returning true for items greater than 9, while the original array stays intact.

Explore array helpers with map and forEach, transforming numbers like 1, 5, 10, 20, and 30, showing how map returns a new array while forEach performs actions only. Note how the original array stays unchanged as map and filter create new results, while forEach executes code without returning a value.

Learn how immediately invoked functions manage scope, use console logs to display results like Francis, and prevent global variable conflicts by wrapping logic and using function arguments.

Learn how JavaScript closures work by returning an inner function that multiplies a captured total by two, and shows how different variables can hold the same closure.

Explore JavaScript built-in string methods, including toUpperCase, toLowerCase, trim, length, charAt, concat, and split, and learn how to manipulate text efficiently.

Explore JavaScript objects, create and access properties with dot and bracket notation, nest objects and arrays, define methods, and modify values to manage complex data.

Explore creating objects in JavaScript using the new keyword and object literals, and learn how to assign properties like name and age and access objects across scripts.

Learn how the this keyword references the parent object within an object, not the window, and how context governs access to properties like name and age.

discover how every object has a default prototype, how to access shared functions like screen via prototype, and why direct prototype access is discouraged in production.

Explore using prototypes in JavaScript by defining a constructor function, creating instances with new, and adding methods to the prototype to share behavior across objects.

Use prototypes and constructor functions as templates to create multiple car objects with shared defaults. Implement prototype methods to check availability and customize models like Ford and Chevy.

Learn how to create a car object with a constructor that accepts brand and color arguments, access and modify properties, check keys with in, and loop through objects and arrays.