title: Cast String to Number in Typescript on JSON API response in Typescript
body: <p>I am making an API call with Axios which returns JSON. The API returns CUSIP as type String, however, I would like to receive it as type Number. I created an interface which has the typescript type as number however when I get the variable, it is still treated as a String.</p>
  
  <p>API Call and some logic:</p>
  
  <pre><code>const axios = require('axios');
  import { General } from './json-objects-new';
  
  module.exports = {
      makeApiCall : function(ticker:string) {
  
      axios.get(`${API_ENDPOINT}${ticker}?api_token=${API_KEY}`)
          .then(function (response) {
              // handle success    
              return response.data;
  
          })
          .catch(function (error) {
              // handle error
              console.log(error);
          })
          .then(data =&gt; {
  
              let gen : General = data.General;
  
              let num = gen.CUSIP + 1337
  
              console.log(num);
  
          });
  
      }
  }
  </code></pre>
  
  <p>interface called General where I cast CUSIP to number:</p>
  
  <pre><code>export interface General {
      ISIN: string;
      CUSIP: number;
  }
  </code></pre>
  
  <p>The problem: instead of printing [CUSIP + 1337] as [2 + 1337 = 1339], it is printing [21337]. Would love some help thanks. I really dont want to have to cast everything manually in a constructor.</p>