This example demonstrates a common source of confusion in JavaScript related to block scope when using the let keyword. The code in bug.js shows how variables declared with let are only accessible ...

Before we get started, we should let you know that many popular mobile browsers don’t allow you to block JavaScript. For example, Firefox on Android or iPhone doesn’t have this feature.

Developing blocks for the Block Editor often involves using modern JavaScript (ESNext and JSX), and most examples here in the Block Editor Handbook are written in these syntaxes. However, this form of ...