Learn React with TypeScript 3

Type aliases

In simple terms, a type alias creates a new name for a type. To define a type alias, we use the type keyword, followed by the alias name, followed by the type that we want to alias.

We'll explore this with the following example:

1. Let's create a type alias for the getTotal method in the OrderDetail interface we have been working with. Let's try this in the TypeScript playground:

type GetTotal = (discount: number) => number;interface OrderDetail {  product: Product;  quantity: number;  getTotal: GetTotal;}

Nothing changes with objects that implement this interface – it is purely a way we can structure our code. It arguably makes the code a little more readable.

2. Type aliases can also define the shape of an object. We could use a ...