What is the difference between optional chaining and nullish coalescing in TypeScript?

What is the difference between optional chaining and nullish coalescing in TypeScript?

Optional chaining (?.) allows you to safely access deeply nested properties without having to check each level for null or undefined. Nullish coalescing (??) provides a way to set default values when dealing with null or undefined values.

Can you give me an example of optional chaining?

Sure! If you have an object user and want to access user.address.city, you can use user?.address?.city. If user or address is null or undefined, it will return undefined instead of throwing an error.

And how does nullish coalescing work?

Nullish coalescing is used like this: const city = user.address.city ?? 'Unknown';. If user.address.city is null or undefined, it will assign 'Unknown' to city.

When should I use one over the other?

Use optional chaining when you want to safely access properties, and use nullish coalescing when you want to provide default values for potentially null or undefined variables.