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How to Load External JavaScript Asynchronously or Dynamically



JavaScript makes more easier to manipulate websites, now a days most of the browsers supporting JavaScript codes. When the HTML parser encounters a <script> element, by default, run the script before it can parsing and rendering the document. It is not much problem for inline scripts but if the script source code is in an external file specified with a src attribute, the portions of the document that follow the Script will not appear in the browser until the script has been downloaded and executed.This makes loading of the website much slower, which makes bad user experience for your website and may not also indexing of your website by the search engines.


This Synchronous or blocking script execution is the default only. The <script> tag can have defer and async attributes, which cause scripts to be executed differently. This makes your website loading much faster than before and appears contents of your site by loading at first.


Loading JavaScript Asynchronously using async or defer attributes



Both the defer and acync attributes are ways of telling the browser that the linked script does not use document.write() and won't be generating document content, and that therefore the browser can continue to parse and render the document while downloading the script. You can use async or defer attributes as the following.
<script defer src="deferred.js"></script> 
<script async src="async.js"></script>

The defer attribute causes the browser to defer execution of the script until after the document has been loaded and parsed and is ready to be manipulated. The async attribute causes the browser to run the script as soon as possible but not to block document parsing while the script is being downloaded. If a <script> tag has both attributes, a browser that supports both will honor the async attribute and ignore the defer attribute. Deferred scripts run in the order in which they appear in the document, while acync scripts run as they load, which means that they may execute out of order.

Here is an example of acync script uses in this blog for Intensedebate comments script source.

<script async='async' expr:src='data:post.commentSrc' type='text/javascript'/>



Loading JavaScript Asynchronously by loading scripts dynamically



You can load and execute scripts asynchronously, even in browsers that do not support the async attribute, by dynamically creating a <script> element and inserting it into the document. Here is an example how to load scripts dynamically.

function loadasync(url){
var head=document.getElementByTagName("head")[0]; 
var s=document.createElement("script"); 
s.src=url;
head.appendchild(s);
}

This loadsaync() function finds the <head> tag and attach <script> tag below opening of head tag and loads scripts dynamically. Scripts that are neither included inline within the web page or referenced statically from the web page are loaded into the document and become part of the running JavaScript program.
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How to Add Multiple Slideshows on One Page Using Javascript



Most of our visitors asked "How to Add Multiple Slideshows on One Page Using JavaScript" by commenting on different previous posts for JavaScript slideshow and going to write this post about to add multiple slideshows on the same page. Using this script you can add number of slideshows on single page as your requirements. 


Multiple Slideshows on One Page Using JavaScript



To make multiple slideshows, at first you have to make variable lists for each slideshows and have to create new slideshow using function slideshow( ). Here I have created two slideshows with variables SlideList1 and SlideList2 and uses function slideshow with parameters slideList, image, speed and name.

You can create number of new slideshows using this function below using new keyword. i.e. var slideshow1=new slideshow(slideList1, 'slide1', 3000, 'slideshow1');

function SlideShow(slideList, image, speed, name)          
{
  this.slideList = slideList;
  this.image = image;
  this.speed = speed;
  this.name = name;
  this.current = 0;
  this.timer = 0;
}

And the another function switchImage( ) given below allows you to  change images while playing slideshows.

function switchImage(imgName, imgSrc) 
{
  if (document.images)
  {
    if (imgSrc != "none")
    {
      document.images[imgName].src = imgSrc;
    }
  }
}

Here is a full JavaScript code for making multiple slideshows on one page using JavaScript. Copy the following codes inside body tag of your HTML file and replace given image source <img src=" "> with your image source.


<img src="image1.gif" name="slide1">
<img src="image2.gif" name="slide2">
<script type=text/javascript>
var SlideList1 = ['image1.gif', 'image2.gif', 'image3.gif'];
var SlideShow1 = new SlideShow(SlideList1, 'slide1', 3000, "SlideShow1");
var SlideList2 = ['image4.gif', 'image5.gif', 'image6.gif'];
var SlideShow2 = new SlideShow(SlideList2, 'slide2', 1000, "SlideShow2");
function SlideShow(slideList, image, speed, name)          
{
  this.slideList = slideList;
  this.image = image;
  this.speed = speed;
  this.name = name;
  this.current = 0;
  this.timer = 0;
}
function switchImage(imgName, imgSrc) 
{
  if (document.images)
  {
    if (imgSrc != "none")
    {
      document.images[imgName].src = imgSrc;
    }
  }
}
SlideShow.prototype.play = SlideShow_play;  
function SlideShow_play()       
{
  with(this)
  {
    if(current++ == slideList.length-1) current = 0;
    switchImage(image, slideList[current]);
    clearTimeout(timer);
    timer = setTimeout(name+'.play()', speed);
  }
}
window.onLoad=SlideShow1.play();SlideShow2.play();
</script>


Here the speed of first and second slideshows are specified 3000 and 1000 respectively, your can change them as your requirements. Also you can add more slideshows by adding more slideList and slideshow variables.

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How to create fade effect image slideshow using CSS



You can give fade effect animation for image slideshow using CSS. @keyframes 'at' rule and animation keyword in CSS can be used to make image slideshow with fade effect. With @keyframes 'at' rule, you can define the properties that will be animated in an animation rule and animation keyword to set all of the animation properties.


Here I have used different types of animation properties like animation-name, animation-duration, animation-timing-function and animation-iteration-count. Where animation-name specifies name of the animation, animation-duration specifies animation duration in second(s) or milisecond(ms), animation-timing-function specifies how the animation will play like ease, ease-in, ease-in-out, ease-out and linear and animation-iteration-count:number of times animation should play.

Simple fade effect image slideshow 

 
Here is a sample CSS code for creating simple fade effect image slideshow written for safari browser.

<style type="text/css">
@-webkit-keyframes fade{
from {opacity:.5;}
50% {opacity:1;}
to {opacity:.5;}
}
#anim1 {-webkit-animation-name:fade;-webkit-animation-duration:5s;
-webkit-animation-iteration-timing-function:linear;
position:relative;-webkit-animation-iteration-count:infinite;}
</style>

Here is a full HTML code along with required JavaScript code for creating simple fade effect image slideshow.

<head>
<title>CSS Animations</title>
<style type="text/css">
@-webkit-keyframes fade{
from {opacity:.5;}
50% {opacity:1;}
to {opacity:.5;}
}
@-moz-keyframes fade{
from {opacity:.5;}
50% {opacity:1;}
to {opacity:.5;}
}
@-o-keyframes fade{
from {opacity:.5;}
50% {opacity:1;}
to {opacity:.5;}
}
@-ms-keyframes fade{
from {opacity:.5;}
50% {opacity:1;}
to {opacity:.5;}
}
#anim1 {-webkit-animation-name:fade;-webkit-animation-duration:5s;
-webkit-animation-iteration-timing-function:linear;position:relative;
-webkit-animation-iteration-count:infinite;-moz-animation-name:fade;
-moz-animation-duration:5s;-moz-animation-iteration-timing-function:linear;
-moz-animation-iteration-count:infinite;-o-animation-name:fade;
-o-animation-duration:5s;-o-animation-iteration-timing-function:linear;
-o-animation-iteration-count:infinite;-ms-animation-name:fade;
-ms-animation-duration:5s;-ms-animation-iteration-timing-function:linear;
-ms-animation-iteration-count:infinite;}
</style>
<script language="JavaScript">
var i = 0;
var path = new Array();
 
// LIST OF IMAGES
path[0] = "image1.jpg";
path[1] = "image2.jpg";
path[2] = "image3.jpg";

function swapImage1()
{
   document.slide.src = path[i];
   if(i < path.length - 1) i++; else i = 0;
   setTimeout("swapImage1()",5000);
}
window.onload=swapImage1;
</script>
</head>
<body>
<div id="anim1"><img height="400" name="slide" src="image_1.gif" width="600" />
</div>
</body>
</html>


In the above code prefixes -webkit-, -moz-, -o-, -ms- are used for browsers safari, firefox, opera and internet explorer respectively.

Here is a preview of image slideshow for the code above.


slide


Fade effect image slideshow with caption


You can add caption for this slideshow by adding following JavaScript codes within <script> tag.


// LIST OF CAPTÄ°ONS  

caption[0] = "Caption for the first image"; 

caption[1] = "Caption for the second image"; 

caption[2] = "Caption for the third image";   

function swapImage(){ 

var el = document.getElementById("mydiv"); 

el.innerHTML=caption[i]; 

var img= document.getElementById("anim1"); 

img.src= image[i];  

if(i <k ) { i++;}  

else  { i = 0; } 



For details on adding caption on image slideshow visit the post: How To Create Simple Image Slideshow Using JavaScript ?


Fade effect image slideshow with caption and link


You can add caption for this slideshow by adding following JavaScript codes within <script> tag.

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How to make rounded corners border using CSS



While designing website, website template or blog template, you may want to make buttons, menus, paragraphs or any others border corners rounded to make your template more beautiful and attractive. It is possible by using a keyword "border-radius" in CSS. The keyword border-radius is used to make all the corners rounded by specifying the radius of corner. For example you can use the following CSS code.
rounded corners border using CSS

border-radius:10px;                    // makes radius of all the corners 10px;

You can also specify the radius for each corners by using border-radius-top-right, border-radius-top-left, border-radius-bottom-right, border-radius-bottom-left keywords. For example you can use the following CSS code to make each corner rounded.

border-radius-top-right:10px;
border-radius-top-left:10px;
border-radius-bottom-right:5px;
border-radius-bottom-left:5px;

The above code makes radius of left and right corners of top side 10px and radius of left and right corners of bottom side 5px.

To makes this CSS code browser specific or specific browser compatible, you have to use the prefix codes like -moz- for mozilla firefox and -webkit- for chrome or safari.
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How to Create Custom CSS Template for Printing



Along with the development of web technologies and web programming languages, web designing becoming more complex and the websites more flexible and user friendly. With the invention of CSS technology, web designing and programming becoming more easier than ever.

By using cascading style sheet (CSS) and its properties, you can give custom design to your website for different medias like screen, print, tv and for different screen sizes. The CSS @media property allows you to do such task.

Today I am going to describe "How to create custom CSS template for printing".

Designing Custom CSS Template for Printing


If you wanted to allow your website visitors to print the content of your website, you can design custom template for printing using CSS. You can define which part or your website will be printed or not and can add page setting for printing.

Designing Custom CSS Template for Printing

Here is a sample CSS code for website template.


body{
     background:#00aaff;
     font-color:#00000;
     font-size:16px;
     }

h1, h2, h3 { 

/* CSS codes for h1, h2, h3 */

}

#wrapper{
        width:80%;
        margin: 0 auto;
        background:#fff;
        padding:20px;
}

#content{
        width:54%;
        float:left;
        margin-right:3%;
}

#header{
       width:100%;
       margin-top:2%;
}

#sidebar-left{
        width:20%;
        float:left:
        margin-right:3%;
}

#sidebar-right{
        width:20%;
        float:left;
}

#footer{
       width:100%;
        }


While printing you can hide default header, menu and sidebar using CSS codes. Here is a sample CSS code for printing webpage.


body{
     background:#00aaff;
     font-color:#00000;
     font-size:16px;
     }

h1, h2, h3 { 

/* CSS codes for h1, h2, h3 */

}

#wrapper{
        width:80%;
        margin: 0 auto;
        background:#fff;
        padding:20px;
}

#header{
       display:none;
}


#content{
        width:100%;
        clear:both;
        margin-right:3%;
}

#sidebar-left{
         display:none;
}

#sidebar-right{
         display:none;
}

#footer{
        display:none;
        }


Place the above CSS code inside media queries for printing as below.

@media only print and (orientation:portrait) { 
    
     /* Add CSS code here for printing on portrait mode */
 }

@media only print and (orientation:landscape) { 
    
     /* Add CSS code here for printing on landscape mode */
 }


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How to Create Responsive Website or Blogger Template



As the time goes, browsing websites from desktop computers decreasing and using Laptops, Tablets and Mobile devices increasing day by day. So why not to create our website design custom for each types of devices, that fits and looks more attractive for those devices to acquire the visitors entered from those devices.

Responsive web design is the approach that suggests in which design and development should respond user behavior and environment based on the size of the browser screen, platform and orientation.

Responsive web design includes the use of flexible layouts, images and intelligent use of media queries. You can make your blogger template responsive by using special tags in CSS. Media queries (@media) are such tags, which helps to make your CSS for every device screen size. You can make many media queries on CSS that matches for each screen size and you can put custom CSS codes for each media queries.

Here I have explained some steps for creating your blog responsive.



Step1: Add meta tags for responsiveness



Add the following meta tags on your blogger template using the following steps.
  1.  Go to blogger dashboard and click on template
  2. Backup your template for the risk while editing template codes.
  3. Paste the following codes between and <head> and </head> tags.
  4. Save your blogger template.
For website also, paste the following codes between <head> and </head> tags.

Add the following codes to size the contents of blog equal to the device width.

  <meta name="viewport" content="width=device-width/">

Add the following codes to size the contents of blog equal to the device width and device height.

  <meta name="viewport" content="width=device-width, height=device-height/">

Add the following codes to size the contents of blog equal to the device width and initial zoom size.

  <meta name="viewport" content="width=device-width, initial-scale=2"/>

Add the following codes to size the contents of blog equal to the device width, initial zoom size and maximum zoom size.

  <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1/">

Instead or writing meta tags, you can do the same with the following codes in CSS.

@-moz-viewport {
                           width: device-width;
}

@-moz-viewport {
                           width: device-width;
                           height:device-height;
}

@-moz-viewport {
                           width: device-width;
                           initial-scale:2;
}

@-moz-viewport {
                           width: device-width;
                           initial-scale:1;
                           maximum-scale:1;
}


This works only for Mozilla browser, for other browsers you can use -o-, -webkit- and -ms- as prefixed properties.
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How to Create Simple Blogger Template Easily?



To create successful blog, it needs to create blogger template more attractive and looks more professional. Even you can buy professional blogger template on the web, you may want to create blogger template by yourself for your blog. Creating a professional blogger template is more challenging task, but if you have some knowledge on HTML, XML, CSS and JavaScript, it is possible to create professional blogger template easily by yourself. In this series of tutorial, I am going to teach you basic to advanced steps to create blogger template. Today I am telling you "steps for creating a simple blogger template" with describing basic elements and along with its corresponding style sheet codes.


Step1: Preparing demo blog for creating blogger template



To test blogger template you have created, at first you need to set up a blogger blog and have to add some posts on the blog. To create a blog, go to blogger home page, log in using your Google user name and password and then click on create a blog link to get started. Write posts for a blog by clicking on create a new post button from the blogger dashboard.


Step2: Creating basic elements for blogger template


Open Notepad file write the codes according to the following format and save it as .xml extension.

# Creating XML Part


At first, add the following codes for  Document Type Deceleration(DTD) on XML part.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1 -strict.dtd">
<html expr:dir='data:blog.languageDirection' xmlns='http://www.w3.org/1999/xhtml' xmlns:b='http://www.google.com/2005/gml/b' xmlns:data='http://www.google.com/2005/gml/data' xmlns:expr='http://www.google.com/2005/gml/expr'>

# Creating Header Part


After that, add the following header elements like head and title of the blog.

<head>
<title>
<b:if cond='data:blog.pageType == "index"'>
<data:blog.pageTitle/>
<b:else/>
<b:if cond='data:blog.pageType != "error_page"'>
<data:blog.pageName/> | <data:blog.title/>
<b:else/>
Page Not Found | <data:blog.title/>
</b:if>
</b:if>
</title>
</head>

# Creating CSS Part


Add custom css codes for your template in the following format. The css codes must be placed inside <![CDATA[*/ and ]]>
tag.

body{
font:normal normal 14px Verdana,Geneva,sans-serif;
color:#000;padding:0 40px 40px 40px;
background:#fff;
font-size:14px;
}
#outer-wrapper{
CSS for outer-wrapper
}
#header-wrapper{
CSS for header-wrapper
}
#titlewrapper{
CSS for titlewrapper
}
#descriptionwrapper{
CSS for descriptionwrapper
}
#menuwrapper{
CSS for menuwrapper
}
#contentwrapper{
CSS for contentwrapper
}
#mainwrapper{ 
CSS for mainwrapper
}

# Creating a Menu 


To create menu for a blog, add the code in the following format. Replace URL and name of the tabs. 

<div id='menuwrapper'>
<ul class='FirstLevel'>
<li><a href='http://www.homepage.com/' target='_self'>Home 
</a></li>
<li><a href='http://www.homepage.com/menu1.html' target='_self'>Menu1 
</a></li>
<li><a href='http://www.homepage.com/menu2.html' target='_self'>Menu2 
</a></li>
<li><a href='http://www.homepage.com/menu3.html' target='_self'>Menu3 
</a></li>
</ul></div>

# Creating blog content

To add main blog content part, add these codes to create a widget named Blog1.

<div id='outer-wrapper'>
<div id='header-wrapper'>
<b:section class='header' id='header' maxwidgets='1' showaddelement='no'>
  <b:widget id='HTML1' locked='true' title='Header' type='HTML'>
 </b:widget>
</b:section>
</div>
<div id='content-wrapper'>
<div id='main-wrapper'>
<b:section class='main' id='main' showaddelement='no'>
<b:widget id='Blog1' locked='true' title='Blog Posts' type='Blog'>
</b:widget>
</b:section>
</div>
</div>
</div>



Step3: Creating gadgets on sidebar and footer.


To create sidebar and footer and to add widgets  for them add these code, which allows you to add widgets on sidebar and footer.

<div id='sidebar-wrapper'>
<b:section class='sidebar' id='sidebar' showaddelement='yes'>
</b:section>
</div>

<div id='footer-wrapper'>
<b:section class='footer' id='footer' showaddelement='yes'>
</b:section>
</div>


Step4: Installing blogger template on required blog.


After creating a code file on Notepad in XML format, test it on demo blog. To install prepared template, click on backup and restore button from template option on blogger dashboard. Click on download full template, the xml file will be downloaded. Then go to the required blog then go to Template  ›  Backup / Restore option and browse and upload that xml file. The template will be applied on your blog.




Related Posts:





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List of Top 10 Video Sites



Here are the List of top 10 and the best video sites includes top video websites like youtube.com.

1. Youtube.com:


YouTube allows billions of people to discover, watch and share originally-created videos. YouTube provides a forum for people to connect, inform, and inspire others across the globe and acts as a distribution platform for original content creators and advertisers large and small.
  • Site's Information:

  1. Google Page Rank: 9
  2. Alexa Rank: 3
  3. Google Indexed: 379,000,000
  4. Google Plus: https://plus.google.com/+youtube
  5. Website: www.youtube.com

2. Vimeo.com:


Vimeo is a video-sharing community for original creative work and the people who create it. It gives the best ways to share, discover, and be inspired.
  • Site's Information:

  1. Google Page Rank: 9
  2. Alexa Rank: 100
  3. Google Indexed: 187,000,000
  4. Facebook: http://www.facebook.com/Vimeo 
  5. Twitter: http://twitter.com/Vimeo 
  6. Instagram: http://instagram.com/vimeo
  7. Tumbler: http://vimeo.tumblr.com/ 
  8. Website: http://vimeo.com/

3. Dailymotion .com:


Dailymotion is one of the biggest video platforms in the world and the most popular European site. Dailymotion offers the best content from users, independent content creators and official partners in the media and entertainment industries all over the world.
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Objective Questions of Data Structure with Answer set-6



1. .......................... is a variable that can hold the address of the variables, structure and functions that are used in the program.

A) Array

B) Pointer

C) Structure

D) None of the above



2. .................. is the organization of the data in a computers memory or in a file.

A) Array

B) Data Structure

C) Data Management

D) Data Organization



3. Which of the following is/are the advantages of using an array?

i) Multi huge quantity of data items can be stored.
ii) Arrays saves the memory space
iii) Arrays helps to arrange the data items in particular order.
iv) Data item searching is faster.

A) i, ii and iii only

B) ii, iii and iv only

C) i, iii and iv only

D) All i, ii, iii and iv



4. Some examples of data structures are

i) array
ii) stack
iii) queue
iv) binary tree
v) hybrid tree

A) i, ii, iii and iv only

B) ii, iii, iv and v only

C) i, ii, iii and v only

D) All i, ii, iii, iv and v



5. Match the following components of data structure based on the concept of Abstract Data Type (ADT) with their definitions.
a) Operations                 i) Organizations of data implemented in lower level data structure.
b) Storage structures     ii) Description on how to manipulate information in the storage structure.
c) Algorithms               iii) Specifies the external appearance of data structure.

A) a-i, b-ii, c-iii

B) a-ii, b-iii, c-i

C) a-iii, b-i, c-ii

D) a-i, b-iii, c-ii



6. Match the following properties of an array with their descriptions.

a) Homogeneous     i) the list size is constant.
b) Ordered              ii) there is a first and last element.
c) Finite                  iii) there is a next and previous in the natural order of the structure
d) fixed-length        iv) every element is the same.

A) a-i, b-ii, c-iii, d-iv

B) a-ii, b-iii, c-iv, d-i

C) a-iii, b-i, c-ii, d-iii

D) a-iv, b-iii, c-ii, d-i



7. Which of the following are linear type of data structure?

i) Linked list
ii) Stack
iii) Binary Tree
iv) Array
v) Queue

A) i, ii, iii and iv only

B) ii, iii, iv and v only

C) i, ii, iv and v only

D) All i, ii, iii, iv and v



8. Which of the following are non linear type of data structure?

i) Tree
ii) Graphs
iii) Hash tables
iv) List

A) i, ii and iii only

B) ii, iii and iv only

C) i, iii and iv only

D) All i, ii, iii and iv




9. State whether the following statements is/are True or False.

i) An ancestor is any node in the path from the root to the node.
ii) A sub-tree is any connected structure below the root.
iii) Binary tree is a directed tree in which out degree of each node is less than or equal to one.
iv) A tree consists of finite set of elements called nodes.
v) Nodes that are not root and not leaf are called intermediate nodes.

A) True, True, True, False, True

B) True, False, True, True, False

C) True, True, True, False, False

D) True, True, False, True, False



10. In a binary search tree the node to be deleted will have two cases which are

i) An empty left sub-tree and non empty right sub-tree and vice versa.
ii) Non empty left sub-tree and right sub-tree.
iii) Empty left sub-tree and right sub-tree.

A) i and ii only

B) ii, and iii only

C) i and iii only

D) None of the above




View Answers:


1. B) Pointer

2. B) Data Structure

3. D) All i, ii, iii and iv

4. A) i, ii, iii and iv only

5. C) a-iii, b-i, c-ii

6. D) a-iv, b-iii, c-ii, d-i

7. C) i, ii, iv and v only

8. A) i, ii and iii only

9. D) True, True, False, True, False

10. A) i and ii only


Related Posts:

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MCQ on Core Java with Answers set-13



1. Which exception is thrown by the read( ) method of input stream class?

A) Exception

B) ClassNotFoundException

C) read Exception

D) IOException



2. What garbage collection in the context of java?

A) The operating system periodically deletes all of the java files available on the system.

B) Any package imported in a program and not used in automatically deleted.

C) When all references to an object are gone, the memory used by the object is automatically reclaimed.

D) The JVM checks the output of any Java program and deletes anything that doesn't make sense.



3. In order for a source code file, containing the public class test, to successfully compile, which of the following must be true?

A) It must have a package statement

B) It must be named test.java

C) It must import java.lang

D) It must declare a public class named test.



4. Which of the following are true about the Error and Exception classes?

A) Both classes extend throwable

B) The error class is final and exception class is not.

C) The Exception class is final and the Error is not.

D) Both classes implement Throwable



5. Which of the following are true?

A) The void class extends the class class

B) The float class extends double class

C) The system class extends the runtime class

D) The integer class extends the number class



6. How do you create a Reader object from an InputStream object?

A) Use the static createReader() method of InputStream class

B) Use the static createReader() method of Reader class

C) Create an InputStreamReader object passing the InputStream object an an argument to the InputStreamReader constructor.

D) Create an OutputStreamReader object, passing the InputStream object as an argument to the OutputStreamReader constructor.



7. Which of the following is true?

A) The event inheritance model has replaced the event delegation model

B) The event inheritance model is more efficient than event delegation model

C) The event delegation model uses event listeners to define the methods of event handling classes.

D) The event delegation model uses the handleEvent() method to support event handling.



8. Which of the following is the highest class in the event delegation model?

A) java.util.EventListner

B) java.util.EventObject

C) java.util.AWTEvent

D) java.util.event.AWTEvent



9. When two or more objects are added as listeners for the same event, which listener is first invoked to handle the event?

A) The first object that was added as listner.

B) The last object that was added as listner

C) There is no way to determine which listener will be invoked first.

D) It is impossible to have more than one listener for a given event.



10. Suppose that you want to have an object eh handle the TextEvent of TextArea object t. How should you add eh as the event handler for?

A) t.addTextListener(eh);

B) eh.addTextListner(t);

C) addTextListner(eh.t);

D) addTextListner(t,eh);



11. What is the preferred way to handle an object's events in Java 2?

A) Override the object's handleEvent( ) method.

B) Add one or more event listeners to handle the events

C) Have the object override its process Event( ) methods.

D) Have the object override its dispatch Event( ) methods.



12. Which component method is used to access a component's immediate container?

A) getVisible()

B) getImmediate()

C) getParent()

D) getContainer()



13. Which of the following creates a List with 5 visible items and multiple selection enabled?

A) new List(5, true)

B) new List(true, 5)

C) new List(5, false)

D) new List(false, 5)



14. An Applet has its Layout Manager set to the default of FlowLayout. What code would be the correct to change to another Layout Manager?

A) setLayoutManager(new GridLayout());

B) setLayout(new GridLayout(2,2));

C) setGridLayout(2,2);

D) setBorderLayout();



15. How do you change the current layout manager for a container?

A) Use the setLayout method.

B) Once created you cannot change the current layout manager of a component

C) Use the setLayoutManager method.

D) Use the updateLayout method.



16. Which of the following methods can be used to draw the outline of a square within a JAVA.awt.Component object?

A) drawLine()

B) fillRect()

C) drawPolygon()

D) drawPolygon()



17. State true or false

i) JPanel is a class included in awt package

ii) Anonymous classes are mostly used for event handling

iii) Names of anonymous classes must be unique

iv) JOptionPane is an inner class

A) i-false, ii-false, iii-true, iv-true

B) i-true, ii-false, iii-true, iv-false

C) i-false, ii-true, iii-false, iv-false

D) i-true, ii-true, iii-false, iv-true



18. State true or false

i) Java RMI supports distributed objects written entirely in java

ii) Java RMI makes use of stubs and skeleton

iii) In Java RMI an object registers itself with a media server

iv) IDL is interface declaration language

A) True, True, False, False

B) False, True, True, True

C) True, False, True, False

D) True, True, True, True



19. Match the following

a) Datagram Socket        i) UDP connection

b) URL                           ii) provides necessary framework of debugging java programs

c) java.net                      iii) makes it possible to communicate over a network with java programs

d) sun.tools.debug          iv) is a java object that represent WWW address

A) a-i, b-iv, c-iii, d-ii

B) a-i, b-iv, c-ii, d-iii

C) a-ii, b-iii, c-i, d-iv

D) a-ii, b-i, c-iii, d-iv



20. State true or false

i) public can only be assigned to class

ii) protected protects a statement

iii) protected method is never accessible outside the package

iv) friendly variable may be accessible outside class

A) True, True, False, True

B) False, False, False, True

C) False, True, False, False

D) True, False, False, False


View Answers:


1. D) IOException
2. C) When all references to an object are gone, the memory used by the object is automatically reclaimed
3. B) It must be named test.java
4. A) Both classes extend throwable
5. D) The integer class extends the number class
6. C) Create an InputStreamReader object passing the InputStream object an an argument to the InputStreamReader constructor.
7. C) The event delegation model uses event listeners to define the methods of event handling classes.
8. B) java.util.EventObject
9. C) There is no way to determine which listener will be invoked first.
10. D) addTextListner(t,eh);
11. B) Add one or more event listeners to handle the events
12. C) getParent()
13. A) new List(5, true)
14. B) setLayout(new GridLayout(2,2));
15. A) Use the setLayout method
16. A) drawLine()
17. C) i-false, ii-true, iii-false, iv-false
18. A) True, True, False, False
19. A) a-i, b-iv, c-iii, d-ii
20. A) True, True, False, True




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MCQ on Java Programming Language Fundamental set-12



1. A java program is first ................ and ...................

A) executed, run

B) compiled, run

C) run, compiled

D) interpreted, compiled


2. Byte code is also a ...........

A) machine code

B) bit code

C) cryptographic code

D) none


3. A private class is accessible from inside a .................

A) package

B) class

C) method

D) none


4. Consider the statement "x=(a>b)?a:b", then the value of x is 19, if a=19 and b=12

A) true

B) not supported

C) false

D) none of the above


5. Adapter classes are used for ...............

A) code redundancy

B) code reduction

C) code organization

D) none


6. ..................... inheritance is enable by interface in java.

A) min level

B) multiple

C) low level

D) none


7. .................... is generated if a button is clicked in AWT.

A) ItemEvent

B) WindowEvent

C) ActionEvent

D) MouseEvent


8. Using which keyword we can access value of the instance and class variables of that class inside the method of that class itself.

A) super

B) final

C) this

D) either super or this


9. If a variable is declared FINAL, it must include ......................... value.

A) integer

B) number

C) initial

D) float


10. In java, string is a

A) primitive data type

B) abstract data type

C) combination of boolean

D) None of the above


11. Methods can be overloaded with a difference only in the type of the return value

A) Not supported

B) False

C) True

D) None of the above


12. Each method in a java class must have a unique name

A) Not necessarily

B) True

C) False

D) None of the above


13. It is an important feature of java that it always provides a default constructor to a class

A) Not supported

B) False

C) True

D) None of the above


14. If one or more abstract methods are not implemented in an abstract class, then the subclass is also abstract.

A) Not necessarily

B) False

C) True

D) None of the above


15. Life cycle of an applet is described by .................. methods.

A) six

B) three

C) four

D) five


16. Which of the following is not subclass of "writer" stream.

A) FileWriter

B) LineWriter

C) BufferedWriter

D) PrintWriter


17. In java RMI, stub is located in

A) client machine

B) proxy

C) server

D) none of the above


18. The new keyword will

i) create in instance of an object

ii) create instance of a class

iii) assign memory to an array

iv) call the destructor of a class

A) i and iii

B) ii and iii

C) i and ii

D) ii, iii and iv


19. ODBC stands for

A) Object Data Binding Command

B) Open Database Console

C) Open Database Connectivity

D) Open Database Command


20. Continue statement can be used

i) anywhere inside main method

ii) anywhere inside class

iii) within instance methods

iv) only within looping statements

A) i, ii and iii

B) i and iv

C) only iv

D) ii, iii and iv





Show/Hide Answers:




1. A java program is first ................ and ...................

B) compiled, run

2. Byte code is also a ...........

D) none

3. A private class is accessible from inside a .................

B) class

4. Consider the statement "x=(a>b)?a:b", then the value of x is 19, if a=19 and b=12

A) true

5. Adapter classes are used for ...............

B) code reduction

6. ..................... inheritance is enable by interface in java.

B) multiple

7. .................... is generated if a button is clicked in AWT.

C) ActionEvent

8. Using which keyword we can access value of the instance and class variables of that class inside the method of that class itself.

C) this

9. If a variable is declared FINAL, it must include ......................... value.

C) initial

10. In java, string is a

B) abstract data type

11. Methods can be overloaded with a difference only in the type of the return value

B) False

12. Each method in a java class must have a unique name

A) Not necessarily

13. It is an important feature of java that it always provides a default constructor to a class

C) True

14. If one or more abstract methods are not implemented in an abstract class, then the subclass is also abstract.

C) True

15. Life cycle of an applet is described by .................. methods.

C) four

16. Which of the following is not subclass of "writer" stream.

B) LineWriter

17. In java RMI, stub is located in

A) client machine

18. The new keyword will

i) create in instance of an object

ii) create instance of a class

iii) assign memory to an array

iv) call the destructor of a class

A) i and iii

B) ii and iii

C) i and ii

D) ii, iii and iv

19. ODBC stands for

A) Object Data Binding Command

B) Open Database Console

C) Open Database Connectivity

D) Open Database Command

20. Continue statement can be used

i) anywhere inside main method

ii) anywhere inside class

iii) within instance methods

iv) only within looping statements

C) only iv



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MCQ on Basic SQL Queries with Answers set-1



1. DML is provided for

A) Description of logical structure of database

B) Addition of new structure in the database system.

C) Manipulation & processing of database

D) Definition of physical structure of database system


2.'AS' clause is used in SQL for

A) Selection operation

B) Rename Operation

C) Join operation

D) Projection Operation


3. Count function in SQL returns the number of

A) values

B) distinct values

C) groups

D) columns


4. The statement in SQL which allows to change the definition of a table is

A) Alter

B) Update

C) Cteate

D) Select


5. Which of the following is correct.

A) A SQL query automatically eliminates duplicates

B) SQL permits attribute names to be repeated in the same relation

C) A SQL query will not work if there are no indexes on the relations

D) None of the above


6. Which of the following operation is used if we are interested in only certain columns of a table?

A) PROJECTION

B) SELECTION

C) UNION

D) JOIN


7. Which of the following is a legal expression in SQL?

A) SELECT NULL FROM EMPLOYEE;

B) SELECT NAME FROM EMPLOYEE;

C) SELECT NAME FROM EMPLOYEE WHERE SALARY=NULL;

D) None of the above


8. Which of the following is a valid SQL type?

A) CHARACTER

B) NUMERIC

C) FLOAT

D) All of the above


9. Which command is used to select distinct subject (SUB) from the table (BOOK)?

A) SELECT ALL FROM BOOK

B) SELECT DISTINCT SUB FROM BOOK

C) SELECT SUB FROM BOOK

D) All of the above


10. In SQL, which of the following is not a data definition language commands?

A) RENAME

B) REVOKE

C) GRANT

D) UPDATE



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Solved MCQ on Database Normalization set-1




1. A ..................... specifies the actions needed to remove the drawbacks in the current design of database.

A) 1 NF

B) 2 NF

C) 3 NF

D) Normal form



2. A relation is in ........................... if an attribute of a composite key is dependent on an attribute of other composite key.

A) 2NF

B) 3NF

C) BCNF

D) 1NF



3. Fifth Normal form is concerned with

A) Functional dependency

B) Multivalued dependency

C) Join dependency

D) Domain key



4. A table is in the ....................... if only candidate keys are the determinants.

A) functional dependency

B) transitive dependency

C) 4 NF

D) BCNF



5. In 2NF

A) No functional dependencies exist.

B) No multivalued dependencies exist.

C) No partial functional dependencies exist

D) No partial multivalued dependencies exist.


6. The normal form that is not necessarily dependency preserving is

A) 2NF

B) 3NF

C) BCNF

D) 4NF



7. The ................. is related to the concept of multi-valued dependency.

A) fourth normal form

B) fifth normal form

C) boyce codd normal form

D) third normal form



8. Which normal form is considered adequate for normal relational database design?

A) 2NF

B) 5NF

C) 4NF

D) 3NF



9. Dependency preservation is not guaranteed in

A) BCNF

B) 3NF

C) 4NF

D) DKNF



10. A relation is ................... if every field contains only atomic values that is, no lists or sets.

A) 1 NF

B) 2 NF

C) 3 NF

D) BCNF



Answers:



1. A ..................... specifies the actions needed to remove the drawbacks in the current design of database.

D) Normal form

2. A relation is in ........................... if an attribute of a composite key is dependent on an attribute of other composite key.

B) 3NF

3. Fifth Normal form is concerned with

C) Join dependency

4. A table is in the ....................... if only candidate keys are the determinants.

D) BCNF

5. In 2NF

C) No partial functional dependencies exist

6. The normal form that is not necessarily dependency preserving is

A) 2NF

7. The ................. is related to the concept of multi-valued dependency.

A) fourth normal form

8. Which normal form is considered adequate for normal relational database design?

D) 3NF

9. Dependency preservation is not guaranteed in

A) BCNF

10. A relation is ................... if every field contains only atomic values that is, no lists or sets.

A) 1 NF





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Solved MCQ on C++ Programming Language set-7



1. What is required in inheritance to initialize the data members of the base class through derived class?

A) Object declaration

B) Destructor

C) Constructor

D) Inheritance


2. In which case is it mandatory to provide a destructor in a class?

A) Almost in every class

B) Class for which two or more than two objects will be created

C) Class for which copy constructor is defined

D) Class whose objects will be created dynamically


3. Which of the statements is true in a protected derivation of a derived class from a base class?

A) Private members of the base class become protected members of the derived class

B) Protected members of the base class become public members of the derived class

C) Public members of the base class become protected members of the derived class

D) Protected derivation does not affect private and protected members of the derived class


4. When the access specifier of the base class in the derived class definition is public, the base class is ..

A) Publicly inherited

B) Protectedly inherited

C) Privately inherited

D) None of the above


5. A pointer to the base class can hold address of

A) only base class object

B) only derived class object

C) base class object as well as derived class object

D) None of the above


6. A template class

A) is designed to be stored in different containers

B) works with different data types

C) generates objects which must be identical

D) generates classes with different numbers functions


7. The constructor and the destructor of a class are automatically invoked when memory is allocated and deallocated to an ....

A) Data type

B) Copy constructor

C) Object

D) None of the above


8. A pure virtual function is a virtual function that

A) has no body

B) returns nothing

C) is used in base class

D) both (A) and (C)


9. A class defined within another class is

A) Nested Class

B) Inheritance

C) Containership

D) Encapsulation


10. Which variable stores the memory address of another variable?

A) Reference

B) Pointer

C) Array

D) None of the above



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MCQ on c++ Programming with Answers set-6



1. If a class C is derived from class B, which is derived from class A, all through public inheritance, then a class C member function can access.

A) Protected and public data only in C and B

B) Protected and public data only in C

C) Private data in A and B

D) Protected data in A and B


2. Overloading the function operator

A) requires a class with an overloaded operator

B) requires a class with an overloaded [ ] operator.

C) allows you to create objects that act syntactically like functions.

D) usually make use of a constructor that takes arguments.


3. What is a constructor?

A) A function called when an instance of a class is initialized.

B) A function that is called when an instance of a class is deleted.

C) A special function to change the value of dynamically allocated memory

D) A function that is called in order to change the value of a variable.


4. Mechanism of deriving a class from another derived class is known as .........

A) Polymorphism

B) Single Inheritance

C) Multilevel Inheritance

D) Message Passing


5. RunTime Polymorphism is achieved by ..........

A) friend function

B) virtual function

C) operator overloading

D) function overloading


6. Which of the following is the proper declaration of a pointer?

A) int x;

B) int &x;

C) ptr x;

D) int *x;


7. In multiple inheritance

A) the base classes must have only default constructors

B) cannot have virtual functions

C) can include virtual classes

D) None of the above


8. for (; ;)

A) means the test which is done using some expression is always true

B) is not valid

C) will loop forever

D) should be written as for( )


9. The compilers converts all operands upto to type of the largest operand is called as ............

A) typeconversion

B) expression

C) evaluation

D) precedence


10. The keyword FRIEND does not appear in

A) the class allowing access to another class

B) the class desiring access to another class

C) the private section of a class

D) the public section of a class



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objective type questions in c programming language set-6




1. Which symbol is used as a statement terminator in C?

A) !

B) ~

C) #

D) ;


2. If the size of the array is less than the number of initializes then, ..........

A) extra values are being ignored

B) generates an error message

C) size of array is increased

D) size is neglected when values are given


3. In C, if you pass an array as an argument to a function, what actually gets passed?

A) Value of elements in array

B) First element of the array

C) Base address of the array

D) Address of the last element of array


4. How many times the following loop be executed? { .. ch='b'; while (ch>='a' && ch<=='z') ch++; }

A) 0

B) 25

C) 26

D) 1


5. If a=8 and b=15 then the statement x=(a>b) ? a:b;


A) assigns a value 8 to x

B) gives an error message

C) assigns a value 15 to x

D) assigns a value 7 to x


6. What is the output of the following code. int n=0, m=1; do { printf("%d", m); m++; } while (m<=n);

A) 0

B) 2

C) 1

D) 4


7. A C program contains the following declaration int i=8, j=5 what would be the value of following expression? abs(i-2*j)
A) 2

B) 4

C) 6

D) 8


8. The output of the following is . int a=75; printf("%d%%", a);

A) 75

B) 75%%

C) 75%

D) None of the above


9. How many times the following program would print ("abc")? main( ) { printf("\nabc"); main( ); }

A) Infinite number of times

B) 32767 times

C) 65535 times

D) Till the stack does not overflow


10. Which of the following is the correct usage of conditional operators used in C?

A) a>b?c=30:c=40;

B) a>b?c=30;

C) max=a>b?a>c?a:c:b>c?b:c

D) return (a>b)?(a:b)



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Solved MCQ on C Programming Language set-5



1. What will be output of the following C program? #include int main() {int goto=5; printf("%d",goto); return 0;}

A) 5

B) 10

C) **

D) compilation error


2. Output of the following C program fragment is. x=5; y=x++; printf("%d %d", x,y);

A) 5, 6

B) 5, 5

C) 6, 5

D) 6, 6


3. What will be output of the following C program? #include int xyz=10; int main() { int xyz=20; printf("%d", xyz); return 0;}

A) 10

B) 20

C) 30

D) compilation error


4. Following program fragment. main(){ printf("%p\n", main( ) ); }

A) Prints the address of main function

B) Prints 0

C) Is an error

D) In an infinite loop


5. What will be output of the following program? #include int main() {int a=2, b=7, c=10; c=a==b; printf("%d",c); return 0;}

A) 0

B) 7

C) 10

D) 2


6. What is the output of the following program segment? main( ) { long i=65536; printf("%d\n", i); }

A) 0

B) 65536

C) -1

D) 65


7. What will be the output of the program? # include int main() {int a[5]={5,1,15,20,25}; int i, j, m; i=++a[1]; j=a[1]++; m=a[i++]; printf("%d, %d, %d", i,j,m); return0;}

A) 2, 1, 15

B) 1, 2, 5

C) 3, 2, 15

D) 2, 3, 20


8. What is the output of the following program segment? main( ) { int=1; do { printf("%d . . ", i); } while (i--); }

A) 0 . . 1 . .

B) 1 . . 0 . .

C) 0

D) -1


9. Output of the program below is. int i; main( ) { printf("%d", i); }

A) 1

B) 0

C) -1

D) Null


10. What will be the output of the following program? main( ) { int i=5; printf("%d", i=++i==6); }

A) 0

B) 7

C) 6

D) 1

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