When should I use union types in TypeScript?

Can you explain when to use union types in TypeScript?

Union types in TypeScript allow you to define a variable that can hold multiple types. You should use them when a value can be one of several types.

Can you give me an example of a union type?

Sure! For instance, you can define a variable as string | number, meaning it can hold either a string or a number.

Are there any downsides to using union types?

One downside is that it can make your code less predictable, as you need to handle multiple types. Type narrowing is essential.

How do I narrow down the type when using union types?

You can use type guards, like typeof or instanceof, to check the type at runtime and narrow it down accordingly.