How do I create a parameter decorator in TypeScript?

Can you explain how to create a parameter decorator in TypeScript?

Sure! A parameter decorator is a special kind of decorator that can be applied to a method parameter. It allows you to modify or observe the parameter's behavior.

What is the syntax for creating a parameter decorator?

The syntax involves defining a function that takes three arguments: the target, the method name, and the parameter index. Here's a simple example:

function LogParameter(target: any, methodName: string, parameterIndex: number) {
    console.log(`Parameter at index ${parameterIndex} in method ${methodName}`);
}

Can you show me how to use this decorator in a class method?

Absolutely! You can use the @LogParameter decorator in a class method like this:

class Example {
    greet(@LogParameter name: string) {
        console.log(`Hello, ${name}!`);
    }
}

What are some practical use cases for parameter decorators?

Parameter decorators can be useful for logging, validation, or injecting dependencies into methods, enhancing the functionality of your classes.