JavaScript Fundamentals for Beginners

Use browser dev tools to create and run code snippets in the sources workspace, with a built-in code editor and watch panel to monitor console outputs.

Learn to convert strings to numbers with parse float and parse int, handle NaN, format with toString and toFixed, and grasp floating point limits and infinity in JavaScript.

Explain undefined and null as JavaScript values signaling missing data; undefined means declared but not assigned, while null signifies intentional absence and serves as a placeholder for a future value.

Learn to convert values to strings in JavaScript using toString, the string constructor, and template literals. Convert numbers and booleans to strings, and embed expressions with template literals.

Convert strings to numbers, booleans, and floats in JavaScript, use parse int and parse float, convert true/false, and handle empty or space strings as zero.

Predict JavaScript type coercion outcomes for expressions mixing numbers, strings, booleans, and null. Understand how plus, minus, times, and division convert values, including concatenation and pixels.

Merge arrays using the spread operator or concat to form a single grocery list from fruits, vegetables, and dairy, expanding elements while the original lists remain unchanged.

Explore multidimensional arrays in JavaScript, including 2d grids and matrices; access and modify elements by row and column, then flatten with flat and reduce for sums.

Master conditional control flow with the if…else statement in JavaScript, learning truthy and falsy values, else if chains, and practical examples like buying a drink.

Practice the ternary operator to classify numbers as even or odd, implement login status checks with conditional output, and categorize numbers into negative, zero, positive small, and positive large.

Explore let and const in depth, covering block scope, updating and redeclaring inside and outside blocks, and how const preserves references such as arrays or objects while preventing reassignment.

Practice implementing spread and rest parameters in JavaScript by building a function that sums prices with a tax rate, using rest prices and a spread array in tests.

Learn default and optional parameters in JavaScript for beginners by building greet customer and apply discount functions with loyalty levels, discount rates, and coupons.

Explore immediately invoked function expressions (IIFEs) to create private scopes, execute code instantly, pass arguments, and prevent global pollution in JavaScript.

Learn to edit movie details in a watch list using a function with optional parameters, preserve existing values with null coalescing, and toggle the watched flag safely.

Learn to search for a movie by name in a watch list using case-insensitive matching, display its details, and view all movies by refactoring into a shared print function.