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angulargoogle-mapstypescript
Azimbek Makhmudov
Azimbek Makhmudov

Reputation: 1

Typescript interface

I have a typescript interface: 

export interface LatLng {
  constructor(lat: number, lng: number): void;
  lat(): number;
  lng(): number;
}

And array with a type of LatLng:

path: Array<LatLng>;

How can i push elements to this array ?

Upvotes: 0

Views: 235

Answers (2)

alexKhymenko
alexKhymenko

Reputation: 5598

Implement interface 

export class LatLngNew implements LatLng {
 constructor(public lat: number, public lng: number) {}
}

You can write like this

this.path.push(new LatLngNew(2,3))

Also you can define array type like this

path: LatLng[];

Upvotes: 2

Nitzan Tomer
Nitzan Tomer

Reputation: 164177

If you only have an interface then you should not have the constructor there and it should look like this:

export interface LatLng {
    lat(): number;
    lng(): number;
}

You can then push a new item like so:

path.push({
    lat: function() { return 0; },
    lng: function() { return 0; },
});

You can also create a factory function for it:

function createLatLng(lat: number, lng: number): LatLng {
    return {
        lat: function() { return lat; },
        lng: function() { return lng; }
    };
}

If you want a class then you do it like so:

class LatLng {
    constructor(private _lat: number, private _lng: number) {}

    lat() {
        return this._lat;
    }

    lng() {
        return this._lng;
    }
}

And push a new instance like so:

path.push(new LatLng(0, 0));

Upvotes: 1

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