在typescript中绑定接口构造函数有什么简写吗？

Question

I'm new in typescript world and I know it is possible to bind arguments of constructor to the class like this

class user {
     constructor(private username:string){}
}

instead of

class user {
     constructor(username:string){
           this.username = username;
      }
 }

I just wonder is it possible to do similar thing with interfaces? for example:

interface IUser{
    username:string;
}

class User implements IUser  {
    constructor( private data:IUser ){
    }
}

Answer 1

There's no shorthand. You will need to map the properties from the object being passed in to the instance of the class. You can do that in a number of ways . Here's an example:

class User implements IUser  {
    username: string;

    constructor(data: IUser) {
        Object.keys(data).forEach((key) => {
            this[key] = data[key];
        });
    }
}

Just be aware that in this example if the passed in object has additional properties then that will map those to your object as well.

By the way, a the shorter method is to use Object.assign . assign is a new ES6 function on Object . You could use the polyfill found on the linked to site to make it work in runtime environments that don't support it.