Here’s a brief summary of the differences between forEach(), for-in, and for-of loops to keep handy as reference. forEach() The forEach() prototype* method, introduced in ES5, executes a provided callback function (a function passed to another function as an argument) once for each value in Array, Map (made up of key-value…

There are two methods of defining a function in JavaScript: the function expression and function declaration. They’re similar, but there are a few important differences you should be aware of. First, here are some things they have in common: No Return Statement? Functions don’t require an explicit return statement. Without…

Immediately Invoked Function Expressions (IIFEs) Explained An imediately invoked function expression (IIFE), pronounced ‘iffy’, is a JavaScript design pattern often used to minimize naming conflict and create private variables. The conventional format for an IIFE is to enclose the whole function within the grouping operator (a set of parentheses) and…

Introduced in the JavaScript specification update ECMAScript6 (2015), the keywords let and const have largely overtaken var for variable declaration. For instance, section 5.1.1 of the Google JavaScript Style Guide instructs that you: Declare all local variables with either const or let. Use const by default, unless a variable needs…

The terms “statement” and “expression” are thrown around quite a bit in the JavaScript world. But what do they mean? Statement A statement is a line of code that performs some action. For example, if, while, and for are statements; they perform actions or control actions but don’t resolve to values. …