Creating Custom Typescript Types

In TypeScript you can build your own custom object types. Custom types work just like any other type. You can use it like this:

type Vehicle = {
    make: string, 
    model: string, 
    capacity: number, 
}

//now we can use the vehicle type in a definition
const corolla: Vehicle = {
    make: "Toyota",
    model: "Corolla", 
    capacity: 5,
}

If you define a vehicle without any of the required types, TypeScript will provide an error stating which property is missing from the object. For example:

const corolla: Vehicle = {
    make: "Subaru",
    model: "Outback", 
}

This definition will provide an error Property 'capacity' is missing in type '{ make: string; model: string; }' but required in type 'Vehicle'., because the capacity property is missing.