This article contains a list of the most frequently asked interview questions and answers for Bootstrap interviews.
This will help both experienced and inexperienced candidates pass the interview.
Let\’s get started!!
The Most Frequently Asked Bootstrap Interview Questions And Answers
#1) Describe Bootstrap?
Answer: Bootstrap is a front-end framework used to create HTML, CSS, and JS web applications. Its design is responsive, fast, and simple to use. It primarily focuses on developing mobile applications with design templates. You can also design interactive components such as drop-down menus, forms, buttons, button groups, alerts, cards, tabs, and many more.
#2) Why is Bootstrap used for mobile app development?
It is used for mobile application development because it has several responsive features and user-friendly design templates. In other words, it employs a mobile-first strategy.
#3) What are the main characteristics of Bootstrap 4?
It has the following features:
It is free and open-source.
Almost all modern browsers, including Google Chrome, Firefox, Safari, Opera, and Internet Explorer, are supported.
Features that are responsive.
Simple to use.
Lightweight.
It is made up of several components and utilities.
Plugin support for jQuery.
Simple to personalise.
Mobile-friendliness.
Integration is simple.
Excellent documentation support.
A large number of templates, themes, and plugins are available.
#4) Identify the key components of Bootstrap 4.
Its main components are as follows:
Bootstrap, which is built on a responsive grid system, has a 12-column grid.
JS Plugins: This section contains JS and jQuery plugins.
CSS: CSS files are included.
#5) What do you mean by the term container?
Containers are the most fundamental Bootstrap components. It functions as a container for HTML code, and it is a section of the page where the site\’s content can be placed to make it responsive and fast.
#6) What exactly do you mean by Bootstrap ClassLoader?
Bootstrap ClassLoader is a Java component and the main parental class of class loaders.
#7) How many different layouts are available in Bootstrap 4?
In Bootstrap 4, there are two types of layouts.
They are as follows:
- Fixed layout
- Fluid layout
#8: What is the fluid layout?
Answer: The fluid layout is useful when creating an app that spans the entire width of the screen. The fluid layout adapts to the size of the browser.
#9: What is the fixed layout?
The fixed layout is the default layout type; it is also responsive and simple to use. Unlike the fluid layout, it cannot adjust to the size of the browser. In most cases, the fixed layout should be 940px.
#10) How do you show code in Bootstrap?
There are two ways to display code.
They are as follows:
- Using the <code> tag – This method is used to show code inline.
- Using the <pre> tag – This method displays code as a standalone block.
#11) How do you round an image in Bootstrap 4?
Answer: You can round an image by using the.rounded class.
#12) What exactly is a progress bar?
A progress bar is an indicator that shows the status of a specific process.
#13) Identify the contextual classes associated with the progress bar.
The contextual classes associated with the progress bar are as follows:
- The .bg-primary class
- The .bg-secondary class
- The .bg-white class
- The .bg-light class
- The .bg-dark class
- The .bg-success class
- The .bg-danger class
- The .bg-warning class
- The .bg-info class
=> For more information, please see our progress bar tutorial.
#14) What are Bootstrap\’s responsive utility classes?
Responsive utility classes in Bootstrap are a collection of classes that are used to hide or show HTML elements based on screen resolution as determined by media query in Bootstrap.
\”hidden-md-down\” is an example.
#16) Describe Bootstrap 4 thumbnails.
Answer: It is a method of using layout images, videos, text, and so on in a grid system. We can make thumbnails by wrapping the image in a tag with the.img-thumbnail class.
#17) Describe the modal in Bootstrap4.
A model is an inherited window that is layered on top of its parent window. This is used to improve the user experience and add new features. The modal plugin is used to create model windows.
#19: Which Bootstrap classes are used for pagination?
The.pagination class, the.page-item class, the.page-link class, the.pagination-sm class, the.pagination-lg class, the.active class, and the.disabled class are the classes used for pagination.
More information about the above classes can be found in the table below:
| Class | Function | |
|---|---|---|
| 1 | The .pagination class, the .page-item class and the .page-link class | These three classes are used to create basic pagination. |
| 2 | The .pagination-sm class | It creates small pagination while decreasing the font size and spacing of the pagination nav. |
| 3 | The .pagination-lg class | It creates large pagination while increasing the font size and spacing of the pagination nav. |
| 4 | The .active class | It highlights the current page. |
| 5 | The .disabled class | It makes the page link un-clickable. |
#20) Describe the collapsing elements in Bootstrap.
Answer: You can collapse any specific element without using any JavaScript code.
To use this feature in Bootstrap, add data-toggle=\” collapse\” to the controller element as well as a data target to automatically assign control of a collapsible element. We can use this by writing.collapse(options), for example.
#21) What are the various button styles in Bootstrap 4?
Answer: There are numerous button styles available in Bootstrap 4.
Among them are:
- Buttons with colors
- Buttons with a colored outline
- Small buttons
- Large buttons
- Block-level buttons
- Button links
=> For more information, please see the button tutorial.
#22) What exactly are Bootstrap alerts?
Bootstrap alerts are used to create presume alert messages that include styles to make the messages more visible to the user.
To create colourful alerts, use the contextual classes listed below:
- The .alert-primary class
- The .alert-secondary class
- The .alert-info class
- The .alert-light class
- The .alert-dark class
- The .alert-success class
- The .alert-danger class
- The .alert-warning class
=> For more information, please see our alerts tutorial.
#23) How is Bootstrap 3 performing?
Answer: A Bootstrap well is a type of container that thrives or makes content appear recessed on a web page. It also uses the.well class to wrap the content.
#24) Describe the functions of the Bootstrap carousel plugin.
The carousel plugin in Bootstrap is used to create sliders on web pages or on your website. Several carousel plugins are used in Bootstrap to display large amounts of content in a small amount of space by using sliders.
.carousel(options),.carousel(\’pause\’),.carousel(cycle\’),.carousel(\’prev\’),.carousel(\’next\’) are some examples.
#25) What will the output of the following code be, and why?
<div class=\”progress\”>
<div class=\”progress-bar bg-success\” style=\”width: 65%\”>
<span class=\”sr-only\”>75% completed</span>
</div>
<div class=\”progress-bar bg-warning\” style=\”width: 20%\”>
<span class=\”sr-only\”>30% with warnings</span>
</div>
<div class=\”progress-bar bg-danger\” style=\”width: 15%\”>
<span class=\”sr-only\”>15% did not complete</span>
</div>
</div>
If we use multiple bars with the same.progress parent element, Bootstrap will combine them into a single progress bar. As we all know, the progress bar sum in Bootstrap is 100%. As a result, the progress bar will display the full width and fully populated result.
#24) How can we customise the pagination links?
Answer: To make the links unclickable, we can use the.disabled class, and to indicate the current page, we can use the.active class.
#25) Describe the input groups in Bootstrap4.
Answer: The input group is output from the controls.
Using the.input-group-prepend and.input-group-append classes, we can prepend and append addons elements to a.form-control in front of or behind text inputs. You can also create a small input group with the.input-group-sm class and a large input group with the.input-group-lg class.
#28) Briefly describe how a navbar works.
Answer: A navbar is an essential feature for creating a responsive meta component that functions as navigation headers for your application and site. As the available viewport width increases, the navbar collapses and becomes horizontal in the mobile view.
#27) How do you make a tabbed navigation menu?
Answer: A tabbed navigation menu can be created by creating a basic unordered list with the.nav base class and the.nav-tabs class.
#28) How do you make a pill navigation menu?
Answer: A pills navigation menu can be created by creating an unordered list with the.nav-pills class as the base class.
#29) What are the two ways to make a navbar in Bootstrap 4?
Answer: We can make a navbar using one of two methods:
Making use of the <ul> and <li> elements
Without the use of the <ul> and <li> elements
#30) What exactly is a breadcrumb?
Answer: A breadcrumb is an effective way to display site hierarchy-based information. This can display information such as the date of publication, categories or tags in a blog, and so on. It may also inform the user of the current page\’s position in a navigational hierarchy.
To make a breadcrumb, we can use the.breadcrumb class.
#31) What are labels?
Labels are used to provide markup on web pages by providing counts, tips, and other information. To indicate labels, we use the label> tag.
#32) What are Bootstrap badges?
Answer: Badges are small labelling components with a low count. To make a badge, we use the.badge class and a contextual class (.badge-*).
#33) What does a jumbotron do in Bootstrap?
Answer: It is used to enlarge headings and add more margin to landing page content. To make a jumbotron, we\’ll need a container div> element with the.jumbotron class.
#34) In Bootstrap, how do we make an image responsive?
To make an image responsive, add the.img-fluid class to the img> tag. The styles.max-width: 100% and height: auto are used. As a result, it complements the parent element well.
#35) What exactly do you mean by \”normalise\” in Bootstrap?
Bootstrap normalise is a small CSS file used to ensure cross-browser consistency.
#36) What are Bootstrap 3 panels?
Panels are DOM components that are used to place your DOM component in a box. To retrieve a basic panel, simply add the.panel class to the div> element. This element can also be given the.panel-default class.
#37: How will you create a Bootstrap 3 panel with headings?
There are two methods for adding panel headings:
The first method is to add heading containers in a panel directly using the.panel-heading class. The second method is to add more styles to the headings by using any heading tag from h1> to h6> with the.panel-title class.
#38) What exactly is lead?
Answer: A lead draws attention to a paragraph. The.lead class is used for this, and it enlarges the font while also increasing the line-height.
#39) In Bootstrap, what is a scrollspy?
It is an auto-updating nav component that allows for the retrieval of sections of the page based on the scroll position. Based on the scroll position, the.active class will update from one nav item to the next.
#40) What is the purpose of the Bootstrap 3 affix plugin?
The answer is that Affix is a jQuery plugin. It enables the div> element to be attached to a specific location on the page.
Use of the social icon on a page as an example. The icons will begin in a specific location, but when the page reaches a certain point, it will block the div> element in place and stop scrolling for the rest of the page.
#41) What is the grid system\’s purpose?
Answer: We can create up to 12 columns across a page using the grid system. For this purpose, various classes have been defined.
#42) In Bootstrap , what are grid classes?
In Bootstrap, there are five grid classes.
They are as follows:
- .col-*
- .col-sm-*
- .col-md-*
- .col-lg-*
- .col-xl-*
The table below contains detailed information about the grid classes.
| Class Prefix | Suitable Device Type | |
|---|---|---|
| 1 | .col-* | For an extra small device (a device with a screen width less than 576px) |
| 2 | .col-sm-* | For a small device (a device with a screen width equal to or greater than 576px) |
| 3 | .col-md-* | For a medium device (a device with a screen width equal to or greater than 768px) |
| 4 | .col-lg-* | For a large device (a device with a screen width equal to or greater than 992px) |
| 5 | .col-xl-* | For an extra-large device (a device with a screen width equal to or greater than 1200px) |
#43) What are the global styles used in the default typography of Bootstrap 4?
These are the solutions:
Native font stack – Font family
Font size – The browser\’s default root font size, which is typically 16px.
1.5 line height
#44: What are the dependencies required for Bootstrap to function properly?
Answer: The only dependency required for Bootstrap to function properly is jQuery.
#45: Describe the purpose of the following code segment.
<a href=\”#\”>Test<span class=\”badge badge-primary\”>30</span></a>
Answer: This code will generate a link with an inline badge that will notify the user of an important notification such as the number of messages received, the number of requests made, and so on. The.badge-primary class will also add a blue colour to the badge.
#46) What is a toast and what are its main components?
Answer: It is similar to a brief appearance of an alert box. The toast header and toast body are the two main components of a toast.
#47) Can you compare the Bootstrap and Foundation frameworks?
Both are well-known front-end frameworks.
A comparison of the two frameworks is provided in the table below.
| Parameter | Bootstrap | Foundation | |
|---|---|---|---|
| 1 | About | The most popular framework for HTML, CSS, and JavaScript | The most advanced responsive front-end framework |
| 2 | Current Version | Version 5 | Version 6 |
| 3 | Developer | Bootstrap Core Team | ZURB |
| 4 | Released in | 2011 | 2011 |
| 5 | Browser support | Almost all modern browsers | Almost all modern browsers |
| 6 | Written in | HTML CSS Less/Sass JavaScript |
HTML CSS Sass JavaScript |
| 7 | Preprocessors | Less / Sass | Sass |
| 8 | License | MIT License | MIT License |
| 9 | Official website | https://getbootstrap.com/ | https://get.foundation/ |
| 10 | GitHub stars | 149k | 29k |
#48) Can you explain Glyphicons in Bootstrap 3?
Glyphicons are reusable components that provide beautiful icons (also known as glyphs) in a variety of categories. It can be used almost anywhere in your code. Glyphicons not only provide icons or glyphs, but also support for dropdowns, input groups, navigation, alerts, and other features.
<span class=”glyphicon glyphicon-search”></span>
Glyphicons are not supported by Bootstrap 4. As a result, when working with v4, you can use the icon sets listed below.
Iconic Octicons by Font Awesome
#49) What is the purpose of the Bootstrap transition plugin?
In modals, it provides simple transition effects such as sliding or fading.
#50) Describe the idea of creating a basic form in Bootstrap.
First, insert a form> element. Wrap labels and controls in a div> element with the.form-group class inside the form element. The.form-control class is then applied to text input elements such as input>, textarea>, and select> elements.
#51) What are your options for incorporating Bootstrap into your project?
There are several ways to incorporate Bootstrap into your project.
They are as follows:
Using compiled CSS and JS code that is ready to use.
Making use of source files.
Using the Bootstrap CDN to install.
Using package managers such as NPM, Yarn, RubyGems, Composer, and others to install.
#52) Is there a connection between Bootstrap and JavaScript?
Yes, there is a connection between the two technologies. JavaScript is required for some Bootstrap components to function properly.
The following are some of the JavaScript-required components:
Alerts – To disable alerts
Buttons – Toggling buttons
Checkbox – For use with checkbox functionality.
Radio button – Used to implement radio button functionality.
Carousels – For carousel sliding behaviour
Dropdowns – Used to display and position dropdowns.
Modals – Used to display, position, and scroll modals.
Navbar – To add responsive behaviour to the collapse plugin.
Toasts – Used to display and dismiss toasts.
Tooltips – Used to display and position tooltips.
Popovers – Used to display and position popovers.
Scrollspy – For updating scrolling behaviour and navigation.
#53) What are some alternatives to Bootstrap?
There are numerous alternatives. Some of them are shown in the list below.
Bulma\’s Foundation Comes to Life
- Foundation
- Bulma
- Materialize
- Material Design Lite
- Skeleton
- Pure CSS
- Semantic UI
- Uikit
#54) Can we learn Bootstrap without first learning CSS?
The straightforward answer is no. Because it is a CSS framework, we cannot learn it without first learning CSS. As a result, understanding the fundamental concepts of Bootstrap requires knowledge of CSS.
#55) In Bootstrap 4, what is flexbox?
Flexbox is a layout module for flexible boxes. Without using float or positioning, you can easily create a flexible layout design with flexbox.
#56) What class is used to make a Bootstrap 4 table dark?
To give a Bootstrap 4 table a dark colour, we can use the.table-dark class.
These interview questions and answers will help you succeed in any Bootstrap interview, whether you are a beginner or an experienced professional. And these are the most frequently asked questions in interviews.
We hope that this article has helped you understand the fundamentals and advanced level of Bootstrap.
We wish you the best of luck in your interview!!