Which is the in-house JavaScript library developed by Yahoo!?

What is the return type of 'typeof ' for standard JavaScript objects?

What is the return type of the hash property?

Which HTML tag is used to group the options of the select menu widget?

The property used to specify the key type when pressed is ______.

What is the purpose of the assign() method?

What will be the output of the following JavaScript code?

<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML = Math.floor(4.7);
</script>

What will be the output of the following code snippet?

<script type="text/javascript" language="javascript"> var a = "Abekus"; var result = a.substring(2,4); document.write(result); </script>

<script>
function my_function()
{
  var first_str = "tatter tots is love";
  var first_pattern = /\f/;
  var result = first_str.search(first_pattern);
  document.getElementById("demo").innerHTML = result;
}
</script>

The main difference between the variables declared with var and with let is __________