title: How to get a leading '+' for positive numbers in Intl.NumberFormat?
body: <p>I'm using Intl.NumberFormat to convert a number type to a formatted string in typescript/javascript in Angular2. I want a native solution and this is ideal, but I need a leading plus sign to be included for positive numbers. </p>
  
  <p>If this is not possible with Intl.NumberFormat how else might I do it <em>natively</em>?</p>
  
  <pre><code>@Input() amount : number;
  
  drawLabel() {
     var formatter = new Intl.NumberFormat("en-GB",
                                           {
                                              style: "decimal",
                                              minimumFractionDigits:1
                                           });
     ...
  
     this.label = formatter.format(this.amount)
  }
  </code></pre>