What are optional types in TypeScript?

What are optional types in TypeScript?

Optional types in TypeScript allow you to define properties that may or may not be present in an object. You use a question mark (?) after the property name to indicate that it's optional.

Can you give me an example of how to use optional types?

Sure! Here's an example:

interface User {
  name: string;
  age?: number; // age is optional
}

const user1: User = { name: 'Alice' };
const user2: User = { name: 'Bob', age: 30 };

What happens if I try to access an optional property that is not defined?

If you try to access an optional property that is not defined, TypeScript will not throw an error, but it will return undefined. You can check for its existence before using it.

Are there any best practices for using optional types?

Yes, it's best to use optional types when a property is truly optional. Avoid overusing them, as it can lead to unclear code. Always consider if a default value might be more appropriate.