title: How to resolve “_this is undefined” in angular 4
body: <pre><code>connect=()=&gt;{
      this.api=new trovaSDK_Init("normal",this.businessKey,"user","user@gmail.com","","","",this.apiCallBack,this.url,this.port);
  };
  
  apiCallBack=(e:any)=&gt;{
      console.log(this.api);
  };
  </code></pre>
  
  <p>After compiling in <code>apiCallBack</code> <code>this</code> key word becoming <code>_this</code> and giving error <code>_this is undefined</code></p>
  
  <p>How to solve it?</p>