Document Object Model And Event Handling MCQ question and answer in javascript with solution

These features are at the heart of jQuery’s power and utility:
1. An expressive syntax (CSS selectors) for referring to elements in the document
2. An efficient query method for finding the set of document elements that match a CSS selector
3. A useful set of methods for manipulating selected elements
4. Powerful functional programming techniques for operating on sets of elements as a group, rather than one at a time
5. A succinct idiom (method chaining) for expressing sequences of operations.

The jQuery library defines a single global function named jQuery(). This function is so frequently used that the library also defines the global symbol $ as a shortcut for it.

jQuery() is a factory function rather than a constructor: it returns a newly created object but is not used with the new keyword) jQuery objects define many methods for operating on the sets of elements they represent, and most of this chapter is devoted to explaining those methods.

The code to ask for the set of all div elements in a document is
var divs = $("div");

The css() method operates on the jQuery object returned by $(), and returns that same object, so that the show() method can be invoked next in a compact “method chain.”

The min means the minimised version of the library, with unnecessary comments and whitespace removed, and internal identifiers replaced with shorter ones.

The jQuery() function (a.k.a) $()) is the most important one in the jQuery library. It is heavily overloaded, however, and there are four different ways you can invoke it.

The equivalent replacement of $(document).ready(f) is $(f).

jQuery.noConflict() is the utility function in jQuery.

jQuery.parseJSON() is used for parsing JSON text.