Adding a HTTP header to the Angular HttpClient doesn't send the header, why?

Question

Here is my code:

import { HttpClient, HttpErrorResponse, HttpHeaders } from \'@angular/common/http\';

Answer 1

First, you need to add HttpHeaders with HttpClient

import { HttpClient,HttpHeaders  } from '@angular/common/http';

your constructor should be like this.

constructor(private http: HttpClient) { }

then you can use like this

   let header = new HttpHeaders({ "Authorization": "Bearer "+token});

   const requestOptions = {  headers: header};                                                                                                                                                                            

    return this.http.get(url, requestOptions)
        .toPromise()
        .then(data=> {
            //...
            return data;
    });