title: how to change null to empty value in http get request angular 8
body: <p>I am using angular to fetch data from API which has some values as null, I want to change this values to an empty string.</p>
  
  <p>sample JSON from API</p>
  
  <pre><code>[
      {
          "id": 84,
          "employee_name": "Alan",
          "phone_number": "",
          "process": null,
          "joining_date": null
      },
      {
          "id": 85,
          "employee_name": "Bob",
          "phone_number": "",
          "process": {
              "id": 1,
              "process_name": "Moulding"
          },
          "joining_date": null
      },
  ]
  </code></pre>
  
  <p>I have successfully changed these null values to an empty string while displaying them in a material table. But that means repeating the same code many times, so I want to do this transformation at a higher level i.e. on an HTTP get request.</p>
  
  <p>api get request</p>
  
  <pre><code>public getAll(): Observable&lt;any[]&gt; {
     return this.http.get&lt;any[]&gt;(`${this.apiURL}/${this.specificURL}/`);
    }
  </code></pre>
  
  <p>I think it can be done using rxjs 'map' operator but I really don't know how to do it.</p>