Top 40 UI Developer Interview Questions and Answers [Updated]


User Interface Developers, undoubtedly, belong at the top of the hierarchical chain of the IT industry owing to their complex role and high paying salary. A UI Developer must consider many factors to develop a web application or software. One primary requirement of the job is creativity. A User Interface Developer employs logical thinking and a few psychological concepts to stimulate audio and visual senses to create a software that is understandable, easy to use and pleasing to the eye. The job also includes technical knowledge and skill as the core to designing and developing a software that is not only flawless in design but also informative in the way that it provides the user with the solution he is looking for to deliver the best User Experience. 

Below is a curated list of some of the User Interface Developer questions most frequently asked by the interviewers in a UI Developer Interview process, including Markup languages, HTML, Semantic elements, Scripting, Storage and many other questions covering concepts from a Beginner to an Advanced level.

Most Frequently Asked UI Developer Interview Question and Answers

What is the role of a UI Developer?

Ans : UI Developer is responsible for creating functional User Interfaces that are convenient, meet the user’s needs and are easy to access, understand and interact with to receive or give a response.

What is the difference between a UI Developer and a UX Developer?

Ans: UI Developer is mostly responsible with the appearance and design of the app, the aesthetics. Colours, patterns, designs and other elements that make an application appear attractive to the end user. On the other hand, a UX Developer is responsible for the technicalities that ensure the functioning and expected performance of an app to deliver enhanced user experience.

What is the difference between a UI Developer and Front-end Developer?

Ans : The UI Developers focus on making an application user-friendly and engaging while the Front-end Developers test and work on the client-side interface in detail to ensure its proper functioning.

What kind of skills do you think are crucial for a UI Developer?

Ans : UI Developers must possess two sets of skills:

Hard Skills – HTML, CSS, JavaScript, Wireframing & Prototyping, Coding, Interaction Designing, Visual Communication.

Soft Skills – Curiosity, Analytics, Communication, Logical thinking, Creativity, and Copywriting.

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Name three ways to reduce a page’s load time?

Ans : Page load time can be reduced by trimming down JavaScript parsing, minimizing redirects, and compressing files. 

What is HTML?

Ans : The HyperText Markup Language or HTML is a  markup language that helps create a basic structure for a webpage to display the required content and other elements.

What is Semantic HTML?

Ans : Semantic HTML or Semantic Markup, are tags that classify the text and separate it from other Semantic elements to clarify the intent of the content in the webpage and the webpage itself. 

Explain the difference between the and tags.

Ans : A tag is used to bold the selected words and are mostly for conventional writing formats whereas, the tag stresses on the importance of the words and emphasizes not only the word but also highlights the semantics.  

Name at least three position property attributes.

Ans : Absolute, Fixed, Relative, Inherent and Static are position property attributes.

. Explain the differences between the quartet of position properties: Relative, Absolute, Static, and Fixed.

Ans : Static – an undeclared position for an element automatically files the element as static in the CSS. Static positioning is the default position.  

  • Relative – relative elements’ position can be changed from the current position based on the space you mention. 
  • Absolute – an absolute positioning allows the placement of any page element anywhere you want it by using the position attributes to set a location. 
  • Fixed – a fixed page element is rooted to the same spot even when you scroll up or down.

. Explain Web Accessibility.

Ans : Web Accessibility is a feature that enables the differently-abled persons to comprehend, interact, and navigate the web. 

. What is JavaScript Hoisting?

Ans : In JavaScript, Hoisting allows all declarations to be moved to the top of the scope before code execution, irrespective of where the  functions and variables are declared.

. What is the difference between HTML and XHTML?

Ans : HyperText Markup Language or HTML is SGML based while Extensible HyperText Markup Language XHTML is XML based. All  content in the HTML can be put in the body but it  needs  to be separated into blocks in XHTML. In short, XHTML is more intensive on structure, conditions and format than HTML. 

. Explain the difference between Local Storage, Session Storage, and Cookies.

Ans :

  • Local Storage – Local Storage provides maximum storage and is cleared when a page or private tab is closed but the data does not expire.
  • Session Storage –  In Session Storage, Pages are only stored for the amount of time the browser or tab is open. The data is cleared as soon as the tab or browser is closed. 
  • Cookies – Cookies store activity information on a server for delivering a personalized experience.

. Discuss the differences between a document and a window.

Ans : A Window object is the first object of the DOM hierarchy. A Document object is within the Window object. HTML elements are accessed through the Document object.

. Does HTML require a compiler?

Ans : Compilers are programs that convert a programming language code into machine code. Considering HTML is a Markup language and not a programming language, it does not require a compiler.  

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. How do floats work?

Ans : Floats help navigate elements to the sides and generally include one of the following four values: 

  • Inherited – the parent’s float value is inherited by an element.  
  • None – since no value is defined, the element stands at the default value and doesn’t float. 
  • Left – The element floats completely to the left side of the container. 
  • Right – The element floats completely to the right side of the container. 

. Name three plugins available in the Bootstrap jQuery plugin library.

Ans : The plugins available in the Bootstrap jQuery plugin library include: 

Alert

Affix, Button, Carousel, Collapse, Dropdown, Modal, Popover, Scrollspy, Tab, Tooltip

. What CSS class should be employed to span 14 columns on medium-sized screens, and eight columns on large screens?

Ans : The CSS class: class=”col-md-14 col-lg-8” should be used.  

. How do you verify if a variable is set in PHP?

Ans : To verify if a variable is set the command !isset($var); can be used.  

. When an error is encountered, how do you differentiate between require () and include ()?

Ans : The require () function stops executing the script when an error is encountered but in the include () function the application continues without a fatal error. 

. What is a CSS reset? How do you differentiate it from normalize.css?

Ans : CSS Resets remove all the default styling on the elements in the browser while a Normalize CSS does not remove the default styling settings. 

. What is an AJAX request, and how can an AJAX request be used?

Ans : Asynchronous Java Script And XML or AJAX requests that provide the user the required data. AJAX calls connect with the servers by using XMLHttpRequests to exchange the data.  

. How do you use HTML5 new tags in IE version eight and earlier?

Ans : The new HTML5 tags are not supported by IE7 and IE8. Using HTML5 tags in IE7 or IE8 would cause errors and result in glitches. Instead, html5shiv.js can be used to run the tags in older browsers.

. What are the effects methods used in jQuery?

Ans :Some effects methods used in jQuery include: 

  • show() – the selected elements are displayed by this feature. 
  • hide() – it causes the selected items to be hidden. 
  • toggle() – it is used to check the visibility of the elements and toggles between the show() and hide() for the selected elements.

. List the types of filters in AngularJS.

Ans :The filters used in AngularJS are 

  • number – formats the numeric data
  • currency – formats numbers into the specified currency 
  • date -formats the date into the prescribed format
  • uppercase – converts a string into uppercase
  • lowercase – converts a string into lowercase
  • filter – filters array in the criteria specified
  • orderby – arrays are ordered by expressions 
  • Json – formats JavaScript objects into JSON strings
  • limit – limits an array to a number of elements

. How do you optimize a website’s assets?

Ans : A website’s assets can be optimized in the following ways: 

  • File compression 
  • File concatenation 
  • Offloading assets 
  • CDN hosting 
  • Code refining and reorganizing.

. What does DOCTYPE mean?

Ans :The DOCTYPE determines the HTML type used on a webpage and a browser uses DOCTYPE to determine how the page is to be rendered or displayed.  

. Explain the difference between standards mode and quirks mode.

Ans :Standards mode was invented to adapt to the modern HTML and CSS specifications whereas, in Quirks mode, the body element is the primary element. Quirks mode is for older browsers.

. What are the limitations to XHTML pages?

Ans :One major limitation faced by XHTML is the lack of browser support. Many browsers cannot parse XHTML as XML, making it a less used Markup language.  

. How to make comments without the text being picked up by the browser?

Ans : Comments starting with “*” and ending with “->” are used to prevent a code from being recognized by the browser.

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. What is the difference between linking to an image, website, and an email address?

Ans :

  • Tags are used to link an image. 
  • The anchor tag is used for hyperlinking and the link must be specified in the href attribute. 
  • The href specification “mailto:send@here.com”  is used to link an email address.

. What would you do when a hyperlink or image is displayed incorrectly?

Ans :The following mistakes cause the image or link to be displayed incorrectly: 

. What is the syntax difference between a numbered list and a bulleted list?

Ans :Bulleted lists are accompanied by the unordered list

      tag. Ordered lists are accompanied by

 

. What is meant by a responsive website?

Ans :A website that functions at any screen resolution and on any system or device such as PC, mobile, laptop, etc., and adjusts to a readable size and is understandable by a user is a responsive website. 

. How do you access a get requests URL parameter with Php?

Ans :To access a get request URL parameter, the Php is: $_GET[“turkey”] 

. What are the new elements in HTML?

Ans :The new HTML elements are graphic tags, semantic tags, and multimedia. Semantic tags include figure, header, footer, and mark. Graphic tags include audio and canvas.  

. Is JavaScript a case-sensitive language?

Ans :When writing in JavaScript, a developer is required to follow the consistent variables, function names, capitalization of letters, and other identifiers to avoid errors in functioning.  

. Explain the layout of HTML in detail.

Ans : HTML layout specifies how the webpage is to be arranged. The HTML5 elements used to define the parts of a webpage are 

  • : it defines the header of a document or a section. 
  • : it defines or specifies a section in the document. 
  • : it defines an independent article. 
  • : it defines the footer of the document.

. Write a JavaScript code to find specific objects in an array of objects.

Ans :Use the JavaScript “find” method. The specific objects can be found by using the code given below: 

let customers = [

  { id: 0, name: 'jane' },

  { id: 1, name: 'tim' },

  { id: 2, name: 'maria' }

];

let customer = customers.find(cust => cust.name === 'maria');

console.log(customer);

--> { id: 2, name: 'maria' }

. What are the ways to improve page performance?

Ans. You can follow the following ways to improve the performance of a web page.:-

  • Always clear cache
  • Minimize the size of the images
  • Make the code fit for mobile browsing
  • Compress HTTP
  • Reduce redirects

. How can a new variable be declared in PHP equal to the number 5?

Ans. To declare a new variable in PHP equal to the number 5 is $number = 5;

. Define the Semantic element’s importance?

Ans. The below reasons will let you know about the importance of Semantic elements.:-

  • These elements structure the code and make it more accessible and consistent for users. 
  • If the semantic elements are used by developers, search engines, and other assisting technologies, then the content and the context should be understandable.
  • Also, the semantic elements enhance the code’s readability, making the developer’s work much easier and quicker.

. Distinguish between the elements Inline, Block, and Inline-block.

Ans. 

Inline: The inline elements in HTML do not begin with the new line; instead, they occur in the same line. In this element, we can add some space to the left and right on it instead of adding space to the bottom & top padding to the page. Examples include span, strong, mark, etc. 

Inline-block: The inline-block elements are similar to inline elements, but they allow the spaces on all sides.

Block: The element block will always begin with a new line. It fills both the left and right spaces of the web page by adding padding and margins. Examples of block elements include div, p, etc.

. Define CSS.

Ans. CSS means Cascading Style Sheets which describe the web pages’ styles which consist of fonts, colors, layouts, etc. We can also define variations and layouts for different types of screens. Moreover, CSS is also useful for XML-based markup languages apart from HTML.

. Distinguish between HTML Tags and HTML Elements.

Ans. HTML tags define the format of content and its display on the web browser. These tags include the components like content, open, and ending tags. On the other hand, HTML elements inform the web browser how to display the text. Further, these elements will become tags when we use brackets <>.

. What are the key benefits of CSS?

Ans. The following are a few of the many benefits of CSS. 

  • It offers users good control over the web page layout.
  • The style files under CSS are made independently of the HTML, so the file size will be smaller.
  • Due to less coding, the files will load much faster. Thus, it increases the website speed.
  • It offers to format changes easily.
  • CSS compatible works across devices.
  • It allows a single CSS to replicate through different web pages, reducing development time.

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. What is meant by event bubbling and event capturing?

Ans. Event bubbling is a procedure of event propagation inside the HTML DOM API. As the event is launched, the element bubbles up the DOM tree. Here we call the child node first, then the parent node. On the other hand, event capturing is different from event bubbling. It is the opposite of event bubbling, where the parent node is called first, then the child node.

. Define the use of and tags.

Ans. The tag is an element used to give an Italic look at the text, whereas the tag is an emphasis element that defines the emphasized text.

. What is meant by the CSS Box Model?

Ans. The CSS Box Model is a type of box that wraps the HTML element. It consists of the assets like actual content, borders, margin, padding, etc. It is all about the design and layout that helps develop a web page’s structure and design.

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With the change in the advancements, we see a profound difference in the working procedures, process and management of the aspects related to the organization. The business organizations are focussing more on the solutions that help in managing the product chains. Many platforms and tools help in providing their immense support to the organizations. Agile PLM (Product Lifecycle Management) is an integrated framework that allows the business teams to work collectively during the development of the product. 

In this article, you can go through the set of Agile PLM interview questions most frequently asked in the interview panel. And these lists will help you to crack the interview as the topmost industry experts curate these at HKR training.

Most Frequently Asked  Agile PLM  Interview Questions

Give a brief idea about the testing principles of Agile testing?

Ans: The following are the principles of Agile testing: 

1. Customer satisfaction 

2. Developing a work environment where the business people and developers work together as a team. 

3. The primary focus should be on the essence rather than lengthy documentation. 

4. Customers would focus on welcoming the changes or developments or enhancements. 

5. Promotion of sustainable development 

6. A big free clean mode 

7. Face to face conversation is encouraged and appreciated. 

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List out a few agile frameworks?

Ans: Below mentioned are the few frameworks of Agile.

  1. Feature-driven development
  2. Test-driven development
  3. Kanban

Give a brief idea about sprint retrospective meetings and release candidate?

Ans: Sprint retrospective meeting: Sprint retrospective meeting is referred to the last part of the sprint. The sprint retrospective meeting is usually done after the review meeting of the sprint. All the teams, along with the scrum master, will join the discussion. The meeting duration would go around 2 to 3 hours.

Release candidate: When developing the applications or the software, there must be no errors or problems behind the work done. Hence, the release candidate is a code or version or a build that is released to ensure that there are no errors in the development stage.

Give a brief idea about the main roles in Scrum?

Ans: There are three main roles in the scrum. They are:

  1. Scrum team: The scrum team includes the individual who is involved in working collectively to complete the set of tasks involved.
  2. Scrum Master: The scrum master is the individual who is responsible for paper execution of the result obtained from the scrum team.
  3. Product owner: The product owner is the individual who is involved in delivering the concept to be built and convey the same idea to the team members.

Describe about zero sprints in Agile?

Ans: A zero sprint in Agile is referred to as the pre-step to be performed before the first sprint. You will need to set up the set of activities that have to be performed before the start of the initial sprint which can be treated as Zero sprint. The activities include backlog preparation, set up the environment to develop, etc.

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Do you think it is possible to apply agile methodology to any other testing apart from development testing and software testing?

Ans: Yes, it is possible to apply agile methodology with any other testing apart from development testing and software testing. The methodology of file testing is applicable in terms of biophysics, biomedical, biochemistry and also in the places that do not have sufficient data. You need to ensure that the project has to be completed within a small team.

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Give a brief idea about the most important agile matrices?

Ans: The most agile matrices are listed below:

Velocity: Velocity is the attribute measured by adding all the estimates of the stories that are approved. This is one of the important attributes that give you a clear idea about the progress, capacity and keeps track of the different aspects.

Work strategy allocation: This attribute gives you a clear idea on the aspect or where exactly you are investing your time and also about the priority of your work.

Defect removal awareness: This attribute allows active members to produce quality products.

Cumulative flow diagram: It allows you to check the uniform workflow, which is represented in the form of a diagram. In the graphical representation, the X-axis represents time, and the Y-axis represents the number of efforts.

Sprint burndown metric: The sprint burndown metric helps in keeping track of the work done with the sprint.

Business value delivered: This is an attribute that is related to the work efficiency of the team involved in the work assigned. It helps in measuring the efficiency and work done with 100 percent as a total mark associated with every project.

Time coverage: The time coverage is referred to as the amount of time given to the code during the testing phase. The time coverage attribute is measured based on the number of lines of code in a ratio format, by the number of relative lines of code.

Defect resolution rate: Defect resolution time is the term that is related to the process in which the team members detect the errors, bugs and fix them.

Describe the build breaker and Kanban?

Ans: Build breaker: There will be some scenarios where the developer will commit a bug accidentally in the software. This accidental bug might cause a problem and interrupt the execution or compilation or with a warning. In such scenarios, it is identified that the build is broken. The main task of the tester is to clear the bug immediately.

Kanban: Kanban is a tool that is designed and developed to help the team in reviewing the work-related aspects, especially the progress of the workflow. The Kanban board is used to describe the status of the current development story.

List out the disadvantages of agile models?

Ans: There are some disadvantages to agile models. They are listed below:

1.The agile models are not easy to predict. If a large project is assigned, then it is not flexible in calculating or getting an understanding of the efforts to be made to work on the project within the given deadline.

2.The product developed will not be a good satisfactory product to the customers, if the client requirements are not understood, analysed and met.

3. Using the agile models, the higher authorities will be able to make precise decisions, which would not be understood by the fresher with a little knowledge.

. Give an idea about test-driven development in Agile?

Ans: Test-Driven environment or often called TDD is a method in which the developer writes an automated test case describing the new addon or function and creates small codes to pass the test.

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. List out the challenges involved in developing Agile Software?

Ans: There are many challenges involved in developing agile software. The most important ones are listed below:

  1. Shows impact on the management rather than the developers.
  2. Each feature has to be completed before moving to the next one.
  3. All the coding part has to be clear and correct to ensure that the application is working as expected.
  4. Much planning is needed while developing agile software.
  5. It requires more testing and involvement of the customers.

. When should you not use Agile?

Ans: You must think of the below aspects before deciding to choose Agile:

  1. Customer availability
  2. Requirements flexibility
  3. Team skills and abilities
  4. Functionality split ability
  5. Time constraint

. What is the product burndown chart, sprint burndown chart, release burndown chart, defect burndown chart?

Ans: Product burndown chart: The product burndown chart is referred to as the descriptive that is represented in the form of a graph showing the implemented product backlog.

Sprint burndown chart: The sprint burndown chart represents the number of implemented sprints and non implemented sprints in the scrum cycle.

Release burndown chart: The release burndown chart is used to depict the pending release.

Defect burndown chart: The defect burndown charr is used to represent the number of defects identified and removed.

Related Article: Agile VS Scrum

. List out the agile quality strategies and project management tools used in Agile?

Ans: The following are the strategies and project management tools used in Agile.

Quality strategies:

  1. Iterations
  2. Dynamic code analysis
  3. Re-factoring
  4. Small feedback cycles                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

project management tools:

1. Agilo

2. Icescrum

3. Version one

4. Agilefant

5. X-Planner

6. Rally software

. What is pair programming and list out its benefits?

Ans: The pair programming is a process in which two programmers work together as a team. One programmer is involved in writing the code and the other programmer reviews the code.

The benefits of pair programming are listed below:

  1. Code quality: The second programmer is involved in reviewing the code, which will help in minimizing the coding errors.
  2. Smooth transfer of knowledge: The experienced individual can teach the other partner about the techniques and codes.

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Conclusion:

Agile PLM is a platform that is used by most of the organizations providing multiple opportunities to the business organizations. It has become popular because of the benefits and frameworks that are helping business organizations achieve their success in a short period. I hope the above information is helpful to you. The above interview questions will help you to crack the interview easily. It is recommended to dep-dive more on the topic so that you will be able to answer any question raised by the interviewer. I wish you all the best for the interview and your excellent career ahead.

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As a Senior Writer for HKR Trainings, Sai Manikanth has a great understanding of today’s data-driven environment, which includes key aspects such as Business Intelligence and data management. He manages the task of creating great content in the areas of Digital Marketing, Content Management, Project Management & Methodologies, Product Lifecycle Management Tools. Connect with him on LinkedIn and Twitter.

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