What are the differences between TypeScript decorators and annotations?

What are the differences between TypeScript decorators and annotations?

TypeScript decorators are special functions that can modify classes, methods, or properties at design time. Annotations, on the other hand, are typically used to provide metadata about a class or method but don't modify their behavior.

Can you give me an example of a TypeScript decorator?

Sure! Here's a simple example of a class decorator:

function LogClass(target: Function) {
    console.log(`Class ${target.name} is created.`);
}

@LogClass
class MyClass {}

What about annotations? How are they used?

Annotations in TypeScript are often used with libraries like Angular. They provide metadata for classes, methods, or properties, helping frameworks understand how to handle them. For example, the @Component annotation in Angular defines a class as a component.

Are decorators and annotations interchangeable?

No, they serve different purposes. Decorators modify behavior, while annotations provide metadata. They complement each other but are not interchangeable.