making decisions between or among conditions

making events happen again and again in JavaScript

grouping code into actionable chunks

collecting properties and values into containers

collecting several items in one container

performing more powerful functions such as transforming and filtering arrays

containing chunks of code for later re-use

delaying and repeating events based on time

making changes to the HTML with JavaScript

responding to unsatisfactory data and actions

reviewing this calendar-oriented built-in object

reviewing this calculation-oriented built-in object

more about JavaScript with the "user agent"

accessing the HTML via JavaScript

listening and responding to events (happenings)

using other people's data sets with this function

employing special workarounds for special cases of strings

concatenating strings with variables in a neater arrangement

using optional shorthand ways to write if/else statements

using optional shorthand ways to write if/else statements

freezing objects to make them

summarizing the famous interface-building JavaScript library

starting a React app without create-react-app

rendering HTML within JavaScript functions

separating concerns within a React app

passing data from a parent to a child component

keeping track of a component's changing variable values

displaying content based on different situations

displaying content from an array of objects

changing the look of the React app based on certain criteria