title: WebStorm “Let definition are not supported by current JavaScript version”
body: <p>I am trying to use new tools available for coding in JavaScript. I've seen the post <a href="https://stackoverflow.com/questions/35772101/phpstorm-let-definition-are-not-supported-by-current-javascript-version">PhpStorm &quot;Let definition are not supported by current JavaScript version&quot;</a>. I've tried as suggested over there, but do not work.</p>
  
  <p>When I hover over the <code>export</code></p>
  
  <blockquote>
    <p>Export declarations are not supported by current JavaScript version</p>
  </blockquote>
  
  <p>When I hover over the <code>yield</code></p>
  
  <blockquote>
    <p>Generators are not supported by current JavaScript version</p>
  </blockquote>
  
  <p>and hovering over the <code>let</code></p>
  
  <blockquote>
    <p>Let definition are not supported by current JavaScript version</p>
  </blockquote>
  
  <p>So the question is how to upgrade the JavaScript version?</p>