在rxjs中使用map方法更改http返回的数据

因为您的服务实际上返回了一个数组,所以您应该使用 .forEach 或 .map

getCalculatedValuesViaGet = (myData): Observable<RmdResponse> => {
    return this._http.get('https://jsonplaceholder.typicode.com/posts',
        {headers: this.getHeaders})
        .map((response: Response) => response.json())
        //the following x contains an array of objects, map to transform the data
        .map(x => {
                //this map is the function of array, not Observable.
                //iterate through each object, and update the value of `title`
                return x.map(y => Object.assign(y, {title: y.title + 'hello world'}))
            }
        )
        .catch(this.handleError);
}