Live Demo: variable let example

<html>
<body>
  <h3>the variable declared with let can only access inside a block, not from outside of the block.</h3>
   <script>
      {
	    let x = 10;
	  // Here x is 10
		document.write("inside block value of x="+x)
	  }
	// variable x can't use here
   </script>
</body>
</html>