What is the difference between optional chaining and null checks in TypeScript?

What is the difference between optional chaining and null checks in TypeScript?

Optional chaining allows you to safely access deeply nested properties without having to check each level for null or undefined. In contrast, null checks require explicit checks at each level.

Can you give me an example of both?

Sure! With null checks, you might write:

if (obj && obj.prop && obj.prop.subProp) {
    console.log(obj.prop.subProp);
}

With optional chaining, it simplifies to:

console.log(obj?.prop?.subProp);

Are there any performance differences between the two?

Generally, optional chaining is optimized for performance in TypeScript, but the difference is negligible for most use cases. It's more about code readability.

When should I use one over the other?

Use optional chaining for cleaner code when you expect properties might be undefined. Use null checks when you need to perform additional logic based on the existence of those properties.