title: ES6 Map features support - too big support in IE11?
body: <p>I'm exploring ES6 few features. To check what is available and where I use:</p>
  
  <p><a href="http://kangax.github.io/compat-table/es6/" rel="nofollow">http://kangax.github.io/compat-table/es6/</a></p>
  
  <p>To play around I use Babel:</p>
  
  <p><a href="https://babeljs.io/repl" rel="nofollow">https://babeljs.io/repl</a></p>
  
  <p>When exploring <code>Map</code> , compatibility table says that</p>
  
  <blockquote>
    <p>constructor arguments are not supported in IE11</p>
  </blockquote>
  
  <p>But I copied sample code:</p>
  
  <pre><code>var result = function() {
    var key1 = {};
    var key2 = {};
    var map = new Map([[key1, 123], [key2, 456]]);
  
    return map.has(key1) &amp;&amp; map.get(key1) === 123 &amp;&amp;
           map.has(key2) &amp;&amp; map.get(key2) === 456;
  }();
  
  console.log(result);
  </code></pre>
  
  <p>executed it in IE11 and to my surprise, result is <strong>true</strong>. <strong>true</strong> was both in Babel (although Babel didn't generate any code) and also in IE 11 console.</p>
  
  <p>Why is that?</p>