title: Is there a functional way to set a variable in javascript?
body: <p>I am looking for something like this:</p>
  
  <pre><code>set("variablename", "value");
  </code></pre>
  
  <p>Why I need this? I want to write the following without creating a new function:</p>
  
  <pre><code>navigator.getUserMedia({ audio: true }, success, fail);
  var success = function(stream) {
     var source = audioCtx.createMediaStreamSource(stream);
  }
  </code></pre>