Ways to determine if an optional parameter has been defined

One method I use to verify if the body property has been passed to the function.

Is there a more straightforward approach in TypeScript?

httpAPI<T>(httpMethod: HttpMethod, url: string, optional?: { params?: HttpParams, body?: any, isUseCache?:boolean }): Observable<T> 
{

    const body: any = optional === undefined || optional.body === undefined ? undefined : optional.body;

}

Answer №1

To start, set a default empty object to return as {}. Next, utilize a shortcut to access the body property.

interface IOptional = { 
  params?: HttpParams, 
  body?: any, 
  isUseCache?:boolean 
};

httpAPI<T>(httpMethod: HttpMethod, url: string, optional?: IOptional = {}): Observable<T> 
{
  const { body } = optional;
}

Alternatively, you can use either lodash get or lodash fp getOr for the same functionality.

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