As with almost every programming language, JavaScript treats various types of values differently. A string like “Hello world” is very different from a number like 42. But what types are ...

Standards proposal would allow annotations to be checked by external type checkers like TypeScript but treated as comments by the JavaScript engine.

JavaScript variables hold a wide variety of information and can be used with virtually any data type. Here's how to use variables to store numbers, text strings, objects, and more.