Implementing the same function twice but with varying argument types

Question

Implementing the same function twice but with varying argument types

Within my TypeScript class, I have the following two methods:

authorize(resource: any, requirement: Requirement) : boolean {
  return false;
}

authorize(resource: any, policy: Policy) : boolean {
  return false;
}

Despite the different argument types (policy and requirement), an error is occurring:

Duplicate function implementation.

I'm puzzled as to why this duplication is happening. Any insights on how to resolve this issue?

What would be the best approach to tackle this problem?

typescript

Answer 1

Answer №1

In TypeScript, there is a feature called function overloading which allows you to define multiple functions with the same name but different parameter types and return type. However, it is important that the number of parameters remains the same.

add(a: string, b: string): string;

add(a: number, b: number): number;

add(a: any, b: any): any {
  return a + b;
}

I hope this explanation helps you understand function overloading in TypeScript better. For further information, you can visit this link.

Answer 2

In TypeScript, there is a feature called function overloading which allows you to define multiple functions with the same name but different parameter types and return type. However, it is important that the number of parameters remains the same.

add(a: string, b: string): string;

add(a: number, b: number): number;

add(a: any, b: any): any {
  return a + b;
}

I hope this explanation helps you understand function overloading in TypeScript better. For further information, you can visit this link.

Answer 3

Answer №2

To achieve this functionality, you can utilize an interface.

Start by creating an interface that both Policy and Requirement classes will implement:

interface IAuthorizeParam {
    myValue: string;
}

class Policy implements IAuthorizeParam {
    myValue: string = 'Policy';
}
class Requirement implements IAuthorizeParam {
    myValue: string = 'Requirement';
}

class Example {
    authorize(resource: any, authParam: IAuthorizeParam): boolean {
        console.log(authParam.myValue);
        return false;
    }
}


const x: Example = new Example();

x.authorize({}, new Policy());
x.authorize({}, new Requirement());

This setup allows the authorize method to work with any class that implements the IAuthorizeParam interface.

Please note that IAuthorizeParam is just a placeholder name in this example.

Answer 4

To achieve this functionality, you can utilize an interface.

Start by creating an interface that both Policy and Requirement classes will implement:

interface IAuthorizeParam {
    myValue: string;
}

class Policy implements IAuthorizeParam {
    myValue: string = 'Policy';
}
class Requirement implements IAuthorizeParam {
    myValue: string = 'Requirement';
}

class Example {
    authorize(resource: any, authParam: IAuthorizeParam): boolean {
        console.log(authParam.myValue);
        return false;
    }
}


const x: Example = new Example();

x.authorize({}, new Policy());
x.authorize({}, new Requirement());

This setup allows the authorize method to work with any class that implements the IAuthorizeParam interface.

Please note that IAuthorizeParam is just a placeholder name in this example.

Implementing the same function twice but with varying argument types

Answer №1

Answer №2

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