Typescript method overloading using "async" operation

Question

export class Service {

public validate() {
    return async((name: string, dob: string) => {
        //do some operation
    });
};

public validate() {
    return async((name: string, dob: string, address: string) => {
        //do some operation
    });
};

}

Error: Duplicate function implementation

Typescript Ver: 3.8.3

Is it possible to overload the method in the typescript? if "yes" can anyone help to resolve the above methods?

Javascript doesn't have built-in function overloading. https://stackoverflow.com/questions/456177/function-overloading-in-javascript-best-practices — Taras Yaremkiv, Mar 09 '20 at 10:24
Possible duplicate https://stackoverflow.com/questions/13212625/typescript-function-overloading — Taras Yaremkiv, Mar 09 '20 at 10:28
Its possible but they way you are doing thats not an overload of function. check this https://www.typescriptlang.org/docs/handbook/functions.html#overloads — RICKY KUMAR, Mar 09 '20 at 10:34
Does this answer your question? [Is there a way to do method overloading in TypeScript?](https://stackoverflow.com/questions/12688275/is-there-a-way-to-do-method-overloading-in-typescript) — ford04, Mar 09 '20 at 10:39

score 1 · Answer 1 · answered Mar 09 '20 at 10:22

1

I think if I suppose your two validate function return different data type such as int and string then you may do something like this.

function validate():string;

function validate(): number;

function validate(): any {
    return something; //Something can be string or number 
}

What if both return number

    public validate() {
    return async((name: string, dob: string, address: string) => {
        //you can do the operation and check if address is undefined
    });
};

answered Mar 09 '20 at 10:22

sourav satyam

980
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The reason I want to avoid the `if check condition` – Manjunath Davanam Mar 09 '20 at 10:31
But both the methods return type is the same – Manjunath Davanam Mar 09 '20 at 10:31
So you mean to say typescript doesn't support method overloading with the same return type? as of now – Manjunath Davanam Mar 09 '20 at 10:33
Then you can have simply one method that can accept all the parameter and you can check if the parameter is being passed while calling. – sourav satyam Mar 09 '20 at 10:33
"Then you can have simply one method that can accept all the parameter and you can check" This i can do ... Just i'm trying with method overloading concept – Manjunath Davanam Mar 09 '20 at 10:34
I red this blog but i coudn't able do for the async operation https://medium.com/p/c256dd63245a/responses/show – Manjunath Davanam Mar 09 '20 at 10:35
Although I never tried method overloading on typescript you can still check https://howtodoinjava.com/typescript/function-overloading/ link. – sourav satyam Mar 09 '20 at 10:36
Ya the above link will work but for async method, I'm facing duplicate method error – Manjunath Davanam Mar 09 '20 at 10:37
Yes https://medium.com/@kevinkreuzer/typescript-method-overloading-c256dd63245a link have good explanation as well. Ok let me check with using async . – sourav satyam Mar 09 '20 at 10:38

Typescript method overloading using "async" operation

1 Answers1