Declare Lack of Value in zod (optional, nullable and nullish)

In this lesson we discuss how Zod works with TypeScript to handle special types like undefined, null, any, unknown, never and void.

We modify our room booking schema to demonstrate the use of optional and nullable Zod utilities.

By using .optional, we allow a property to be either its original type or undefined. With .nullable, we allow it to be either its original type or null. Finally, .nullish allows a value to be either its original type, null, or undefined.

For all cases, we run tests to show how these schemas work in practice, as well as how TypeScript infers types.