title: How to insert data to JSON file dynamically?
body: <p><a href="https://i.stack.imgur.com/1r5qH.png" rel="nofollow noreferrer">json file img</a></p>
  
  <p>Note: I wanna insert data without write that into .json file. such as Angularfire2 database.</p>
  
  <pre><code> user = {
   name: 'Arthur',
   age: 21
  };
  
  const options = {Headers, responseType: 'json' as 'blob'};
      this.httpService.put('assets/data/ex.json', this.user, options).subscribe(
        data =&gt; {
           console.log(data);
        },
        (err: HttpErrorResponse) =&gt; {
          console.log (err.message);
        }
      );
  </code></pre>