Page 223 - Web Applications (803) Class 12
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2.  Explain typeof operator in JavaScript with example.
                  Ans.  The typeof operator is a type checking operator in JavaScript that returns the datatype of the operand passed
                       to it. The argument for the typeof operator can be any variable, function, or object whose type you want to
                       determine. Example: typeof(“TELEVISION”) will give output as string.
                     3.  Explain substring( ) and reverse( ) functions with examples.

                  Ans.  substring( )—It extracts the substring using the starting and ending positions as parameters. If the ending position
                       is left blank, the string will be extracted from beginning to end.
                       Example: str1 = "Pineapple is very tasty!";
                       document.write(str1.substring(7,20))

                       Output: le is very ta
                       reverse(  )—The  order  of  the  elements  in  an  array  is  reversed  via  the  reverse()  method.  The  original  array  is
                       overwritten.
                       const fruits = ["pear", "pinapple", "guava", "cherry", "olive"]; document.write(fruits.reverse());
                       Output: olive,cherry,guava,pinapple,pear
                     4.  Explain the unshift method in JavaScript.

                    Ans.  The unshift( ) method inserts new elements at the beginning of an array. The original array is overwritten.
                       Example:

                      const col1 = ["blue","green","orange","purple"];
                      col1.unshift("silver", "golden");
                      document.write(col1);
                       Output: silver,golden,blue,green,orange,purple211 Web Scripting—JavaScript
                     5.  How is DOM handled in JavaScript?

                  Ans.  The Document Object Model, or DOM for short, is in charge of determining how distinct objects inside an HTML
                       document communicate with one another. To create web pages, which contain elements like paragraphs and
                       links, DOM is necessary. These items can be controlled to do operations like add and delete. A web page also
                       needs DOM in order to add more features.

                 B.   Long answer type questions.
                     1.  Differentiate between Static websites and Dynamic websites.
                  Ans.
                                         Static Websites                                Dynamic Websites
                       Pages on static websites won't change until they are  Pages  on  dynamic  websites  have  varying  contents
                       manually updated.                                 depending on the visitor.
                       Take less loading time.                           Take more loading time.
                       HTML,  JavaScript,  and  CSS are used to create static  CGI, AJAX, PHP, ASP.NET are used to create dynamic
                       web sites.                                        web sites.
                       Require less effort and cost in designing.        Require more effort and cost in designing.
                     2.  Differentiate between Property and Method through an example.
                  Ans.
                                              Property                                          Method
                       Can be value or function.                             Is a function
                       Defines the characteristics of an object like size, colour etc.  An action performed on objects.


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