When should I use union or intersection types in TypeScript?

Can you explain when to use union types in TypeScript?

Union types are used when a variable can hold multiple types. For example, if a function can accept either a string or a number, you would use a union type like string | number.

What about intersection types? When should I use those?

Intersection types are used when you want to combine multiple types into one. For instance, if you have two interfaces and you want an object to satisfy both, you would use an intersection type like A & B.

Can you give me an example of both in a function?

Sure! For a union type, you might have a function like function log(value: string | number) { console.log(value); }. For an intersection type, you could have function process(value: A & B) { /* ... */ } where A and B are two interfaces.

Are there any performance implications when using these types?

Generally, there are no significant performance implications. However, using complex types can make your code harder to read and maintain, so it's best to use them judiciously.