JavaScript Basics for Beginners

Explore dynamic typing in JavaScript, where variable types change at runtime, using the type of operator to inspect strings, numbers, booleans, undefined, null, and objects.

Explore arithmetic, assignment, comparison, logical, and bitwise operators in JavaScript, used with variables to create expressions that drive logic and algorithms.

Explore how do-while loops differ from while and for loops in JavaScript, showing that a do-while runs at least once and the condition is checked at the end.

Learn how to use the for-in loop to iterate over object properties and array indices, access values with dot and bracket notation, and prepare for the ES6 for-of loop.

implement a javascript checkSpeed function to enforce a 70 km/h speed limit, calculate points using math.floor for every 5 km over the limit, and suspend licenses after 12 points.

Learn to implement countTruthy to count truthy elements in an array with a for-of loop, and grasp truthy versus falsey values like undefined, null, empty string, and not a number.

Create a sum function that returns the total of multiples of 3 and 5 up to a limit, using a for loop, modulo checks, and an explicit final return.

Calculate a student's grade from an array of marks by averaging and mapping the result to a letter grade using a clear range table. Refactor into single responsibility functions.

Learn to implement showPrimes to display all primes up to a limit, using an isPrime helper and the single responsibility principle with early returns to keep code simple.

Explore enumerating properties of a circle object using for in and for of loops, access values with bracket notation, and use object.keys, object.entries, and the in operator to inspect properties.

Explore the string primitive and string object in JavaScript, and learn core methods like length, includes, starts with, ends with, index of, replace, split, escape notation, and template literals.

Learn how template literals in JavaScript, using backticks, simplify multi-line strings, avoid escaping quotes, and interpolate dynamic values with placeholders like ${}, enabling clearer, output-like code.

Create an address object with street, city, and zipCode, then build a showAddress function that uses a for-in loop and bracket notation to log each property and its value.

Learn to work with arrays and perform operations like adding, finding, removing, and splitting or combining elements to build essential JavaScript skills for beginners.

Modify a constant numbers array using push, unshift, and splice to add elements at the end, beginning, or middle. Learn zero-based indexing and inserting items like a and b.

Learn how to replace traditional functions with arrow functions in ES6, including single-parameter, no-parameter, and single-line forms, and pass them as callbacks to methods like find.

Discover four ways to empty a JavaScript array: reassign to a new array, set length to 0, use splice, or loop with pop. Consider references and performance for clean code.

Discover how to combine arrays using the spread operator in ES6, compare with concat, and copy arrays with spread, plus inserting elements between arrays for flexible results.

Explore iterating arrays in JavaScript using for-of and forEach with callback and arrow functions, including optional index, and compare with for-in for indexing.

Explore joining arrays with the join method using an optional separator to create strings, and see how split and join help build a url slug with hyphens.

Create arrayFromRange(min, max) to generate numbers from min to max using a for loop that pushes values into an array and returns it, producing empty array when max < min.

Design and implement a custom includes function that checks whether a given element exists in an array using a for-of loop, returning true or false based on the search.

Explore getters and setters in objects to read and update properties like full name efficiently. Use ES6 method shorthand and a setter to split values into first and last names.

Explore why the var keyword creates function-scoped variables and can attach to the global window object, contrast with let and const for block scope, and learn to avoid global variables.

Learn to add error handling to an array-based function by validating input with Array.isArray, throwing an invalid array error, and wrapping code in a try-catch to log to the console.