Hands-On Design Patterns with React Native

Type inference

The very first thing I want you to understand is type inference. You do not need to type everything. Some types can be inferred by TypeScript.

Imagine a situation where I have told you, "I have put only chocolate donuts in the box on your desk." Since, in this example, I pretend to be the computer, you can trust me. Hence, when you arrive at your desk, you are 100% sure that the box is of the Box<ChocolateDonut[]> type. You know this without opening the box or having an explicit sticker on it that says Box full of chocolate donuts.

In a real code, it works very similarly. Let's look at the following minimal example:

const someVar = 123; // someVar type is number

This is trivial. We can now look at something that I like more, ...