└── README.md /README.md: -------------------------------------------------------------------------------- 1 | # MERN Stack Interview Preparation Questions [ HTML, CSS, JS, REACT, Express, Mongodb] 2 | more than 240 interview preparation questions on MEARN Stack, search on internet and based on peoples experience , open for contribution 3 | 4 | *difficulty level may vary as per people knowledge and how they judge* 5 | ### dont forget to give Star 6 | 7 | | NO | QUESTIONS | DIFFICULTY | TECHNOLOGY | 8 | |-----|------------------------------------------------------------------------------------------------|--------------|------------| 9 | | 1 | What is the difference between inline, internal, and external CSS? | Intermediate | CSS | 10 | | 2 | What is the box model in CSS? | Beginner | CSS | 11 | | 3 | What is the difference between padding and margin in CSS? | Easy | CSS | 12 | | 4 | What is the difference between absolute and relative positioning in CSS? | Intermediate | CSS | 13 | | 5 | What is a media query in CSS? | Beginner | CSS | 14 | | 6 | How can you center an element horizontally and vertically in CSS? | Easy | CSS | 15 | | 7 | What is the difference between display:none and visibility:hidden in CSS? | Intermediate | CSS | 16 | | 8 | What is the difference between relative and absolute units of measurement in CSS? | Intermediate | CSS | 17 | | 9 | What is a pseudo-class in CSS? | Beginner | CSS | 18 | | 10 | How can you make a page responsive in CSS? | Intermediate | CSS | 19 | | 11 | What is the difference between an em and a rem in CSS? | Beginner | CSS | 20 | | 12 | What is a CSS preprocessor? | Intermediate | CSS | 21 | | 13 | What is the difference between a class and an ID in CSS? | Beginner | CSS | 22 | | 14 | What is a CSS framework? | Intermediate | CSS | 23 | | 15 | What is the difference between CSS resets and CSS normalizations? | Intermediate | CSS | 24 | | 16 | What is the box model in CSS? | Easy | CSS | 25 | | 17 | How do you center an element horizontally and vertically in CSS? | Easy | CSS | 26 | | 18 | What is a pseudo-class in CSS? | Easy | CSS | 27 | | 19 | What is a CSS selector? | Easy | CSS | 28 | | 20 | What is the difference between display: none and visibility: hidden in CSS? | Beginners | CSS | 29 | | 21 | What is the difference between em and rem units in CSS? | Beginners | CSS | 30 | | 22 | What is the purpose of a reset.css file? | Beginners | CSS | 31 | | 23 | What is the difference between a CSS framework and a CSS library? | Beginners | CSS | 32 | | 24 | What is the difference between :nth-child and :nth-of-type in CSS? | Beginners | CSS | 33 | | 25 | How do you create a responsive design in CSS? | Beginners | CSS | 34 | | 26 | What is the purpose of the z-index property in CSS? | Beginners | CSS | 35 | | 27 | What is the difference between flexbox and grid in CSS? | Intermediate | CSS | 36 | | 28 | What is the difference between inline-block and block in CSS? | Intermediate | CSS | 37 | | 29 | What is the purpose of the clearfix hack in CSS? | Intermediate | CSS | 38 | | 30 | What is the difference between position: absolute and position: relative in CSS? | Intermediate | CSS | 39 | | 31 | How do you use media queries in CSS? | Intermediate | CSS | 40 | | 32 | What is the purpose of the transition property in CSS? | Intermediate | CSS | 41 | | 33 | What is the purpose of the transform property in CSS? | Intermediate | CSS | 42 | | 34 | What is the purpose of the box-sizing property in CSS? | Intermediate | CSS | 43 | | 35 | What is the difference between :hover and :focus in CSS? | Intermediate | CSS | 44 | | 36 | How do you create a sticky header in CSS? | Intermediate | CSS | 45 | | 37 | What is the difference between @media and @import in CSS? | Experienced | CSS | 46 | | 38 | What is the purpose of the calc() function in CSS? | Experienced | CSS | 47 | | 39 | How do you implement a CSS preprocessor like Sass or Less? | Experienced | CSS | 48 | | 40 | What is the purpose of the content property in CSS? | Experienced | CSS | 49 | | 41 | What is the purpose of the will-change property in CSS? | Experienced | CSS | 50 | | 42 | How do you implement a CSS animation? | Experienced | CSS | 51 | | 43 | What is the difference between :before and :after in CSS? | Experienced | CSS | 52 | | 44 | What is the purpose of the rem unit in CSS? | Experienced | CSS | 53 | | 45 | What is Express.js? | Beginner | Express | 54 | | 46 | How is routing done in Express.js? | Intermediate | Express | 55 | | 47 | What is middleware in Express.js? | Beginner | Express | 56 | | 48 | How can you handle errors in Express.js? | Intermediate | Express | 57 | | 49 | What is the difference between a PUT and a POST request in RESTful APIs? | Intermediate | Express | 58 | | 50 | What is the difference between a GET and a POST request in RESTful APIs? | Easy | Express | 59 | | 51 | What is Express? | Easy | Express | 60 | | 52 | What are the advantages of using Express? | Easy | Express | 61 | | 53 | What is middleware in Express? | Easy | Express | 62 | | 54 | What is routing in Express? | Easy | Express | 63 | | 55 | What is the difference between res.send() and res.json() in Express? | Easy | Express | 64 | | 56 | What is the use of app.use() in Express? | Easy | Express | 65 | | 57 | What is the use of app.listen() in Express? | Easy | Express | 66 | | 58 | What is the purpose of the next() function in Express middleware? | Easy | Express | 67 | | 59 | What is the difference between app.use() and app.get() in Express? | Easy | Express | 68 | | 60 | What is the purpose of app.listen() in Express? | Easy | Express | 69 | | 61 | What is a route handler in Express? | Easy | Express | 70 | | 62 | What is the purpose of the res.send() function in Express? | Easy | Express | 71 | | 63 | How can you serve static files in Express? | Easy | Express | 72 | | 64 | What is the difference between req.query and req.params in Express? | Easy | Express | 73 | | 65 | What is Express Router? | Beginners | Express | 74 | | 66 | What is CORS in Express? | Beginners | Express | 75 | | 67 | What is the difference between a PUT and a POST request in Express? | Beginners | Express | 76 | | 68 | What is the difference between REST and SOAP? | Beginners | Express | 77 | | 69 | What is JWT authentication in Express? | Beginners | Express | 78 | | 70 | What is the difference between synchronous and asynchronous code in Express? | Beginners | Express | 79 | | 71 | What is Express generator? | Beginners | Express | 80 | | 72 | What is error handling in Express? | Intermediate | Express | 81 | | 73 | What is the difference between app.use() and app.all() in Express middleware? | Intermediate | Express | 82 | | 74 | What is Express-session? | Intermediate | Express | 83 | | 75 | What is cookie-parser in Express? | Intermediate | Express | 84 | | 76 | What is body-parser in Express? | Intermediate | Express | 85 | | 77 | What is the purpose of the res.json() function in Express? | Intermediate | Express | 86 | | 78 | What is the difference between HTML and XHTML? | Easy | HTML | 87 | | 79 | What are the new features in HTML5? | Intermediate | HTML | 88 | | 80 | What is the role of DOCTYPE in HTML? | Beginner | HTML | 89 | | 81 | What is the difference between the and elements in HTML? | Easy | HTML | 90 | | 82 | What are the different types of lists in HTML? | Beginner | HTML | 91 | | 83 | What is the difference between a div and a span in HTML? | Easy | HTML | 92 | | 84 | What is the difference between an ID and a class in HTML? | Easy | HTML | 93 | | 85 | What is the purpose of the alt attribute in HTML? | Easy | HTML | 94 | | 86 | What is semantic HTML? | Intermediate | HTML | 95 | | 87 | What is the difference between the and
elements in HTML? | Beginner | HTML | 96 | | 88 | What is the purpose of the title attribute in HTML? | Beginner | HTML | 97 | | 89 | What is the difference between a
and
in HTML? | Easy | HTML | 98 | | 90 | What is the purpose of the target attribute in HTML? | Intermediate | HTML | 99 | | 91 | What is the purpose of the tag in HTML? | Easy | HTML | 100 | | 92 | What is the difference between the
    and
      elements in HTML? | Intermediate | HTML | 101 | | 93 | What is the purpose of the placeholder attribute in HTML? | Beginner | HTML | 102 | | 94 | What is the difference between the and elements in HTML? | Easy | HTML | 103 | | 95 | What is the difference between the
      and
      elements in HTML? | Beginner | HTML | 104 | | 96 | What is the purpose of the
      and
      elements in HTML? | Easy | HTML | 105 | | 97 | What is the purpose of the href attribute in HTML? | Beginner | HTML | 106 | | 98 | What is the difference between the
      and
      elements in HTML? | Easy | HTML | 107 | | 99 | What is the difference between a