Angular 4.3 - HttpClient set params

let httpParams = new HttpParams().set('aaa', '111');
httpParams.set('bbb', '222');

Why this doesn't work? It only set the 'aaa' and NOT the 'bbb'

Also, I have an object { aaa: 111, bbb: 222 } How can I set all the values without looping?

UPDATE (this seems to work, but how can avoid the loop?)

let httpParams = new HttpParams();
Object.keys(data).forEach(function (key) {
     httpParams = httpParams.append(key, data[key]);
});

Before 5.0.0-beta.6

let httpParams = new HttpParams();
Object.keys(data).forEach(function (key) {
     httpParams = httpParams.append(key, data[key]);
});

Since 5.0.0-beta.6

Since 5.0.0-beta.6 (2017-09-03) they added new feature (accept object map for HttpClient headers & params)

Going forward the object can be passed directly instead of HttpParams.

getCountries(data: any) {
    // We don't need any more these lines
    // let httpParams = new HttpParams();
    // Object.keys(data).forEach(function (key) {
    //     httpParams = httpParams.append(key, data[key]);
    // });

    return this.httpClient.get("/api/countries", {params: data})
}