What is the value of c in the following code snippet?

function a(version) {
  this.version = version;
}
a.prototype.version = '1.8';
var b = new a('1.8.1');
delete b.version;
var c = b.version;

Which statement defines a regular expression?

Which property contains user agent string of web browser?

Which statement is true?

What's the output? var somevar; alert(typeof(somevar));

.... property refers to the window that opens another window.

Which is true about setTimeOut()?

Top most object in the object hierarchy?

Which will return all HTTP headers?

Which option is the most maintainable way to attach JavaScript functionality to an HTML element?