What datatype does the async attribute optionally accept?

Which object does the setTimeout() method belong to?

  A function with no return value is called __________ 

<p id = "tuf"></p>

<script>

var a = 987e6;

document.getElementById("tuf").innerHTML = a;

</script>

Which of the following is the event to run code after the page is loaded?

What is the output of the following code?

int num == 1;
if(num == null)
   return 1;
else
   return 0;

What does the following code do?

Which method is used to select an HTML element by its tag name in JavaScript?

What can be done in order to avoid the creation of global variables in JavaScript?