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.

Fortunately, JavaScript’s variable system is incredibly powerful and versatile. This article shows you how to use JavaScript variables to store numbers, text strings, objects, and other data types.

Web storage API There are two types of built-in “web storage” in modern browsers: localStorage and sessionStorage. These give you convenient access to longer-lived data.

Microsoft is opening up Excel to developers with a new JavaScript API. It will let developers use custom data types like images, cards, and arrays.

What’s cool: With six available widgets for Google maps, bar charts, bubble charts and more, users just need to code simple HTML tables and lists in order to generate robust online visualizations.