SGLearn@ES6 Javascript: The Complete Developer's Guide

Explore JavaScript array helper methods like forEach, map, filter, find, and reduce in ES6, learn how these tools replace manual loops, and boost your ability to process data.

Explore the forEach helper to iterate arrays by passing an anonymous iterator function; compare it to a traditional for loop using a colors array, showing reduced boilerplate and readability.

Create an array of numbers and sum its values with forEach, updating a running total and printing the result, while exploring separate iterator functions and practical use cases.

Leverage the for each helper as the practical, go-to tool for array methods, illustrated with a Gmail-style example of deleting selected emails and writing less boilerplate than a for loop.

Explore the map helper by refactoring a for loop that doubles numbers into a map operation. Learn that map returns a new array and requires a return in the iterator.

Continue exploring the map helper by extracting car prices from an array of car objects, creating a prices array of 'cheap' and 'expensive', and discussing plucking properties for client-side rendering.

Learn how to use the map helper to render lists of data in front-end web apps, transforming post objects into html without mutating the original array.

Explore the filter helper by filtering an array of product objects to keep only fruits, producing a non-mutating subset and returning the truthy results.

Master practical ES6 JavaScript filtering with a filter helper to select vegetables with quantity greater than zero and price less than 10.

Learn to use the filter helper to extract comments for a specific post by matching comment.postId to post.id in a blog-like app, demonstrating filtering relational data on the client side.

Learn to query records with the find helper by iterating an array with an iterator function and returning the first match. Compare this to a for loop and a break.

Learn to use the find helper to locate specific items in arrays, such as cars by model or posts by id, returning the first match.

Learn how to use the find helper to locate a post by its id in an in-memory array, enabling dynamic resource selection on a single-page app.

Explore the every and some helpers and how they yield booleans across an array, then compare with reduce.

Explore using the every and some helpers on a computers array to determine if all or any machines have at least 16 gigabytes of RAM, highlighting readability and boolean results.

Master the every and some helpers in ES6 JavaScript by filtering an array of names to those with length greater than four, and evaluating universal versus partial conditions.

Explore how every and some simplify form validation by validating multiple fields like username, password, and birthdate, using a field object and a single every call.

Learn how reduce condenses an array into a single value using an initial value and an iterator, illustrated by summing 10, 20, and 30 to 60.

Learn to use reduce to collect color values from objects into a final array of red, yellow, and blue, starting with an array accumulator and mutating it with push.

Learn to use reduce in JavaScript to check balanced parentheses on a string for whiteboard interviews, turning the string into an array, counting opens and closes, and handling order.

Discover how to declare variables in ES6 with const and let, replacing var, and decide when values should change or stay constant, illustrated by an employee example.

Discover why ES6 uses const and let instead of var, and how declaring unchanged values with const and changing ones with let improves code readability and ease of refactoring.

Explore template strings, or template literals, in ES6 and learn to replace string concatenation with backticks, dollar-sign and curly-brace expressions, and variable interpolation for clearer code.

Learn how template strings replace string concatenation with back ticks and ${} placeholders to make dynamic data easier to read. See refactoring from string concatenation to clean JavaScript templates.

Explore fat arrow functions, replacing the function keyword with an arrow and using implicit returns for single-expression functions.

Master fat arrow functions to write concise es6 code by omitting the function keyword and parentheses for a single argument, and dropping braces and return for a single expression.

Learn how arrow functions in ES6 simplify code and fix this binding issues in callbacks, by replacing traditional function expressions in map with concise, context-aware syntax.

Learn how arrow functions use lexical this to inherit the surrounding context, replacing the function keyword to resolve this and binding issues in JavaScript.