How many methods are there in the History object?

How many reserved words are there in JavaScript?

Which Window object method is used to display a message in a dialog box?

Which is the handler method used to invoke when uncaught JavaScript exceptions occur?

Predict the output:

let a = 3;

let b = "3";

console.log(a === b);
console.log(a == b);

An object's properties are similar to variables; methods are similar to which of the following?

<p id="head">Head</p>
function demo()
{
  var l = document.getElementsByTagName("P").namedItem("head");
  alert(l.innerHTML);
}

Which of the following methods of the String object returns the calling string value converted to uppercase while respecting the current locale?

 What will happen if the body of a for/in loop deletes a property that has not yet been enumerated? 

Predict the output of the following code:

function main()

{ 

console.log('A'); 

setTimeout( function exec(){ console.log('B'); } , 0); 

runWhileLoopForNSeconds(3); 

console.log('C');}

main();

function runWhileLoopForNSeconds(sec)

{ let start = Date.now(),

 now = start; 

while (now - start < (sec*1000)) 

{ now = Date.now(); }

}