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Small practical guide on Flow and TypeScript for JavaScript developers
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Pragmatic types




Small practical guide on statically-typed languages for developers who switching from dynamically-typed languages to statically-typed versions. For example from JavaScript to TypeScript or Flow.

For who

This guide assumes at least some prior knowledge of dynamically-typed languages. The idea of this guide is to help make a mental shift from dynamic to static types.

Most of the time I will use JavaScript and TypeScript or Flow examples. Maybe this will be useful for other languages - I do not know yet, let's see.

If you have prior knowledge of statically typed languages, but Hindley-Milner doesn't ring a bell for you, this guide can be useful for you too.


This is my diary of personal discoveries. I find myself explaining those things again and again to different people. I decided to write it down once and for all.

Table of contents

Similar works


Ideas, questions, and fixes are welcome. Sharing on social networks is also a big help. Thank you.

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