Bootstrap Interview Questions Part 3

11. How to make images responsive in Bootstrap?

Answer:

To make the images responsive, Bootstrap allows you to add a class '.img-responsive' to the tag.

This class sets the maximum width equal to 100% and height to auto such as max-width: 100%; height:auto, so it scales nicely to the parent element.

Example:

<!DOCTYPE html>
<html>
    <head>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    </head>
    <body>
        <div class="container">
            <h2>Responsive Image</h2>             
            <img src="/home/careerride2/Downloads/download.jpg" class="img-responsive" alt="download" width="304" height="236">
        </div>
    </body>
</html>


responsive image

12. What is the purpose of Scrollspy plugin ?

Answer:

Scrollspy plugin allows you to target sections of the page based on the scroll position.

It is used to automatically update links in a navigation list based on scroll position.

Example:

<!DOCTYPE html>
<html>
<head>
  <title>Scrollspy in Bootstrap</title>
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <style>
  body {
      position: relative;
  }
  #page1 {padding-top:10px;height:500px;color: #fff; background-color: #1E88E5;}
  #page2 {padding-top:10px;height:500px;color: #fff; background-color: #673ab7;}
  #page3 {padding-top:10px;height:500px;color: #fff; background-color: #ff9800;}
  #page41 {padding-top:10px;height:500px;color: #fff; background-color: #00bcd4;}
  #page42 {padding-top:10px;height:500px;color: #fff; background-color: #009688;}
  </style>
</head>
<body data-spy="scroll" data-target=".navbar" data-offset="50">
<nav class="navbar navbar-inverse navbar-fixed-top">
  <div class="container-fluid">
    <div class="navbar-header">
        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#myNavbar">
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>                         
      </button>
      <a class="navbar-brand" href="#">Simple Web Pages</a>
    </div>
    <div>
      <div class="collapse navbar-collapse" id="myNavbar">
        <ul class="nav navbar-nav">
          <li><a href="#page1">Page 1</a></li>
          <li><a href="#page2">Page 2</a></li>
          <li><a href="#page3">Page 3</a></li>
          <li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" href="#">Page 4 <span class="caret"></span></a>
            <ul class="dropdown-menu">
              <li><a href="#page41">Page 4-1</a></li>
              <li><a href="#page42">Page 4-2</a></li>
            </ul>
          </li>
        </ul>
      </div>
    </div>
  </div>
</nav>     
<div id="page1" class="container-fluid">
  <h1>Page 1</h1>
  <p>Scroll Down!</p>
</div>
<div id="page2" class="container-fluid">
  <h1>Page 2</h1>
  <p>Scroll Down!</p>
  
</div>
<div id="page3" class="container-fluid">
  <h1>Page 3</h1>
  <p>Scroll Down!!</p>
  
</div>
<div id="page41" class="container-fluid">
  <h1>Page 4 Submenu 1</h1>
  <p>Scroll Down!</p>
   
</div>
<div id="page42" class="container-fluid">
  <h1>Page 4 Submenu 2</h1>
  <p>Scroll Down!</p>
</div>
</body>
</html>


scrollspy plugin

13. What are the two ways to display the code?

Answer:

There are two ways to display the code,

1. <code> tag
2. <pre> tag

The <code> tag is used when you are going to display the code inline.

The <pre> tag is used when you want to display the code as standalone block element or it has multiple lines.

14. What do you know about bootstrap collapsing element?

Answer:

Bootstrap collapsing element enables you to collapse any particular element without writing any Javascript code. You can use '.collapse (options)', '.collapse('show')' or '.collapse (hide)' to apply collapsing elements.

Example:

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  </head>
  <body>
    <div class="container">
      <h2>Collapse in Bootstrap</h2>
      <p>Click on the button</p>
      <button type="button" class="btn btn-info" data-toggle="collapse" data-target="#demo">Show</button>
      <div id="demo" class="collapse">
        Showing content
      </div>
    </div>
  </body>
</html>


collapse bootstrap

15. What is meant by list group in Bootstrap?

Answer:

List groups are components to display both simple and complex element with custom content.

Example:

<ul class="list-group">
  <li class="list-group-item">First</li>
  <li class="list-group-item">Second</li>
  <li class="list-group-item">Third</li>
</ul>

16. What is the use of Bootstrap Carousel plugin?

Answer:

Bootstrap Carousel plugin is used to add a slider to your site. This plugin is useful in condition where you want to display huge amount of contents within a small space on the web pages.
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