title: swap values in ES6
body: <p>I've two variables and i wanna swap them without using third variable.</p>
  
  <p>Ex: </p>
  
  <pre><code>let a = 'value1',
      b = 'value2';
  </code></pre>
  
  <p>Result: </p>
  
  <pre><code>a = 'value2',
  b = 'value1'
  </code></pre>
  
  <p>is this possible?</p>