isES6()

HTML

<script>
	window.isES6 = false;
</script>
<script>
	// Arrow functions support
  () => { };
  
  // Class support
  class __ES6FeatureDetectionTest { };
  
  // Object initializer property and method shorthands
  let a = true;
  let b = { 
  	a,
    c() { return true; },
    d: [1,2,3],
   };
  
  // Object destructuring
  let { c, d } = b;
  
  // Spread operator
  let e = [...d, 4];

  window.isES6 = true;
</script>

<script>
document.body.innerHTML += 'isES6: ' + window.isES6;
</script>