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Web Technologies Questions

Page 1 of 13 (Displaying Questions 1 – 100 of 1207 Total)

1. What is HTML and what is its primary purpose?

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HTML (HyperText Markup Language) is the standard markup language for creating web pages and defining their structure.

Added: Nov 30, 2025

2. What is a semantic element in HTML?

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A semantic element clearly describes its meaning to both the browser and the developer (e.g., <header>, <article>, <footer>).

Added: Nov 30, 2025

3. What is the purpose of the DOCTYPE declaration?

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It tells the browser which version of HTML (or XML) the document is written in, ensuring correct rendering.

Added: Nov 30, 2025

4. How do you include an external CSS file in an HTML document?

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Using the <link> tag within the <head> section: <link rel="stylesheet" href="styles.css">.

Added: Nov 30, 2025

5. What is the difference between a block element and an inline element?

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Block elements occupy the entire width available and start a new line (<div>, <p>). Inline elements only occupy the necessary width and do not start a new line (<span>, <a>).

Added: Nov 30, 2025

6. What is the alt attribute used for in the <img> tag?

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It provides alternative text for an image if the image cannot be displayed, and is crucial for accessibility (screen readers).

Added: Nov 30, 2025

7. How do you open a link in a new tab?

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By adding the target="_blank" attribute to the <a> tag.

Added: Nov 30, 2025

8. What are HTML entities?

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Character codes used to display reserved characters (like < or >) or special characters (like non-breaking space &nbsp;).

Added: Nov 30, 2025

9. Explain the use of the <meta> tag.

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It provides metadata about the HTML document, such as character set, viewport settings, and author information.

Added: Nov 30, 2025

10. What is the difference between the id and class attributes?

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id must be unique per element and is used for styling or scripting a single element. class can be used on multiple elements for applying reusable styles.

Added: Nov 30, 2025

11. How do you embed a video in HTML5?

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Using the <video> tag with the src attribute pointing to the video file, optionally including controls.

Added: Nov 30, 2025

12. What is the purpose of the <canvas> element?

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It is used to draw graphics on a web page, via scripting (usually JavaScript).

Added: Nov 30, 2025

13. What are data attributes in HTML5?

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Attributes prefixed with data- used to store custom data private to the page or application.

Added: Nov 30, 2025

14. How do you make a form field required?

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By adding the required attribute to the input element.

Added: Nov 30, 2025

15. What is the difference between <section> and <article>?

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<article> is for self-contained, independent content. <section> is for grouping related content within an article or the document.

Added: Nov 30, 2025

16. What is the purpose of the aria-* attributes?

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They define ways to make web content and applications more accessible to people with disabilities (WAI-ARIA).

Added: Nov 30, 2025

17. Where should the script tags be ideally placed?

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Just before the closing </body> tag to allow the HTML content to load first, preventing page rendering delays.

Added: Nov 30, 2025

18. What is the role of the defer attribute on a script?

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It tells the browser to download the script in parallel with parsing the document, and execute it after the document has finished parsing.

Added: Nov 30, 2025

19. How is the <figcaption> element used?

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It provides a caption or legend for the content of its parent <figure> element.

Added: Nov 30, 2025

20. How do you specify alternative text for responsive images using srcset?

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The alt attribute is added to the parent <img> tag, which applies regardless of which source is selected from srcset.

Added: Nov 30, 2025

21. What is the default character set in HTML5?

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UTF-8.

Added: Nov 30, 2025

22. What is the function of the <details> and <summary> tags?

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They create a disclosure widget where the content in <details> can be hidden or shown by clicking the <summary>.

Added: Nov 30, 2025

23. How do you make an input field read-only?

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By adding the readonly attribute to the input element.

Added: Nov 30, 2025

24. What does the novalidate attribute do on a form?

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It disables the browser's default form validation when the form is submitted.

Added: Nov 30, 2025

25. What are HTML comments and how are they written?

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Text ignored by the browser, used for developer notes: .

Added: Nov 30, 2025

26. What is an anchor tag?

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The <a> tag, used to define a hyperlink.

Added: Nov 30, 2025

27. How do you specify the input type for an email address?

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Using <input type="email">.

Added: Nov 30, 2025

28. What is the purpose of the name attribute in a form input?

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It is used to identify the form data after it is submitted to the server.

Added: Nov 30, 2025

29. What is the root element in an HTML document?

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<html>.

Added: Nov 30, 2025

30. What is inline styling?

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Applying CSS styles directly to an HTML element using the style attribute.

Added: Nov 30, 2025

31. What is the difference between an HTML element and an HTML tag?

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An HTML tag is the opening or closing marker (e.g., <div>). An HTML element includes the opening tag, content, and closing tag.

Added: Nov 30, 2025

32. How do you create an ordered list and an unordered list?

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Ordered lists use <ol> and list items use <li>. Unordered lists use <ul> and list items use <li>.

Added: Nov 30, 2025

33. What is the role of the <base> tag?

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It specifies the base URL and/or target for all relative URLs in a document.

Added: Nov 30, 2025

34. What is the function of the <time> tag?

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It defines a specific time or a date/time value.

Added: Nov 30, 2025

35. How do you make an input field disabled?

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By adding the disabled attribute to the input element.

Added: Nov 30, 2025

36. What is the "C" in CSS?

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Cascading. It defines how styles flow down from various sources and how conflicts are resolved.

Added: Nov 30, 2025

37. Explain CSS specificity.

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It is the set of rules browsers use to determine which CSS property values apply to an element when multiple rules target it.

Added: Nov 30, 2025

38. What is the CSS Box Model?

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A model that wraps every HTML element in a box consisting of content, padding, border, and margin.

Added: Nov 30, 2025

39. How do you center a block element horizontally?

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Set its width and then set margin: 0 auto;.

Added: Nov 30, 2025

40. What is the difference between display: none; and visibility: hidden;?

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display: none; removes the element from the document flow. visibility: hidden; hides the element but it still occupies its space.

Added: Nov 30, 2025

41. What is Flexbox?

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A one-dimensional CSS layout module designed for arranging items in rows or columns, making alignment and spacing easier.

Added: Nov 30, 2025

42. What is CSS Grid?

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A two-dimensional CSS layout module designed for arranging items in rows and columns simultaneously.

Added: Nov 30, 2025

43. What is a media query?

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A CSS technique used to apply styles based on device characteristics, most commonly screen size, for responsive design.

Added: Nov 30, 2025

44. Explain the z-index property.

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It specifies the stack order of a positioned element (one with position: absolute, relative, fixed, or sticky). Higher values are closer to the user.

Added: Nov 30, 2025

45. What is the difference between em and rem units?

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em is relative to the parent element's font size. rem (root em) is relative to the root HTML element's font size.

Added: Nov 30, 2025

46. What are pseudo-classes? Give an example.

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Keywords added to a selector to specify a special state of the element, such as :hover or :active.

Added: Nov 30, 2025

47. What are pseudo-elements? Give an example.

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Keywords added to a selector to style a specific part of an element, such as ::before or ::after.

Added: Nov 30, 2025

48. How do you clear a floating element?

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Using the clearfix technique (applied to the parent) or setting the parent's overflow: auto;.

Added: Nov 30, 2025

49. What is the default value of the position property?

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static.

Added: Nov 30, 2025

50. What are CSS custom properties (variables)?

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Entities defined by CSS authors that contain specific values to be reused throughout a document. They start with --.

Added: Nov 30, 2025

51. What is vendor prefixing?

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Adding a prefix (like -webkit- or -moz-) to experimental or non-standard CSS properties to ensure compatibility across different browsers.

Added: Nov 30, 2025

52. How does the box-sizing property work?

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It defines how the total width and height of an element are calculated. border-box includes padding/border in the total size.

Added: Nov 30, 2025

53. What is the transition property used for?

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It allows you to define smooth, animated transitions between two states of a property value over a given duration.

Added: Nov 30, 2025

54. What is the purpose of the calc() function?

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It allows you to perform basic arithmetic operations (addition, subtraction, multiplication, division) to set property values.

Added: Nov 30, 2025

55. How do you hide an element without removing it from the document flow?

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Using visibility: hidden; or setting opacity: 0;.

Added: Nov 30, 2025

56. What are keyframes in CSS?

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They are points in a CSS animation sequence where you explicitly define the styles that must occur at specific times (percentages).

Added: Nov 30, 2025

57. What is the difference between min-width and max-width in responsiveness?

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min-width is mobile-first (styles apply when viewport is at least this wide). max-width is desktop-first (styles apply when viewport is at most this wide).

Added: Nov 30, 2025

58. How can you link to a local font file?

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Using the @font-face rule.

Added: Nov 30, 2025

59. What is the initial value keyword?

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It resets the value of a property to its default value as specified in the CSS specification.

Added: Nov 30, 2025

60. What is the purpose of the opacity property?

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It sets the transparency level of an element (from 0.0 to 1.0).

Added: Nov 30, 2025

61. What is the clip-path property used for?

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It is used to create complex shapes for an element's visibility area, hiding parts outside the shape.

Added: Nov 30, 2025

62. How do you apply styles only when an element is focused?

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Using the :focus pseudo-class.

Added: Nov 30, 2025

63. What does the border-radius property do?

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It is used to round the corners of an element's border.

Added: Nov 30, 2025

64. What is the difference between color and background-color?

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color sets the foreground color of text. background-color sets the background color of the element box.

Added: Nov 30, 2025

65. What is the CSS property for creating shadows?

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box-shadow for element boxes and text-shadow for text.

Added: Nov 30, 2025

66. What is JavaScript and how is it primarily used on the web?

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A client-side scripting language used to make web pages interactive and dynamic, handling behavior.

Added: Nov 30, 2025

67. What is the difference between == and ===?

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== performs type coercion (compares values after converting types). === compares values and types strictly (no coercion).

Added: Nov 30, 2025

68. Explain hoisting in JavaScript.

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A mechanism where variable and function declarations are moved to the top of their scope during compilation, though initialization remains in place.

Added: Nov 30, 2025

69. What is a closure?

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The ability of a function to retain access to variables from its parent's scope even after the parent function has finished executing.

Added: Nov 30, 2025

70. What is the DOM?

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The Document Object Model is a programming interface for web documents. It represents the page so that programs can change the document structure, style, and content.

Added: Nov 30, 2025

71. How do you select an element by its ID using JavaScript?

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Using document.getElementById('elementId') or document.querySelector('#elementId').

Added: Nov 30, 2025

72. What is the difference between let, const, and var?

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var is function-scoped. let and const are block-scoped. const variables cannot be reassigned.

Added: Nov 30, 2025

73. What is an event bubble?

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The process where an event triggered on a nested element is first handled by that element, then by its parent, and so on up the DOM tree.

Added: Nov 30, 2025

74. What is the use of the addEventListener method?

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It attaches an event handler to an element without overwriting existing handlers, allowing multiple functions to run on the same event.

Added: Nov 30, 2025

75. How do you make an AJAX request using the modern fetch API?

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Using the global fetch() method, which returns a Promise that resolves to the Response object.

Added: Nov 30, 2025

76. What is a Promise?

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An object representing the eventual completion (or failure) of an asynchronous operation and its resulting value.

Added: Nov 30, 2025

77. Explain the purpose of async and await.

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async defines an asynchronous function that returns a Promise. await pauses the execution of the async function until a Promise is settled (resolved or rejected).

Added: Nov 30, 2025

78. What are template literals?

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String literals enclosed by backticks (`) that allow embedded expressions using ${expression} and support multi-line strings.

Added: Nov 30, 2025

79. What is the spread operator (...) used for?

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To expand an iterable (like an array or string) into its individual elements, often used for merging arrays or copying objects.

Added: Nov 30, 2025

80. What is type coercion?

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The automatic conversion of values from one data type to another during an operation like 5 + '5'.

Added: Nov 30, 2025

81. What is the concept of scope?

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The accessibility of variables, functions, and objects in some particular part of your code. (Global, Function, Block).

Added: Nov 30, 2025

82. How do you check the data type of a variable?

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Using the typeof operator.

Added: Nov 30, 2025

83. What does 'use strict'; do?

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It enables strict mode, which imposes restrictions on certain JavaScript syntax and silences some errors by throwing them instead.

Added: Nov 30, 2025

84. What is JSON?

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JavaScript Object Notation, a lightweight data-interchange format that is easy for humans to read and write, and for machines to parse and generate.

Added: Nov 30, 2025

85. What is prototypal inheritance?

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A mechanism where JavaScript objects inherit features from one another via their prototype chain rather than using traditional class-based inheritance.

Added: Nov 30, 2025

86. What is destructuring assignment?

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A syntax that allows you to unpack values from arrays or properties from objects into distinct variables.

Added: Nov 30, 2025

87. What is the difference between a synchronous and an asynchronous operation?

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Synchronous operations execute sequentially, blocking the main thread. Asynchronous operations execute independently without blocking the main thread.

Added: Nov 30, 2025

88. What are higher-order functions?

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Functions that either take one or more functions as arguments or return a function as a result (e.g., map, filter).

Added: Nov 30, 2025

89. How do you handle errors in a Promise chain?

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By using the .catch() method at the end of the chain.

Added: Nov 30, 2025

90. What is the Event Loop?

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A fundamental concurrency model in JavaScript that handles asynchronous callbacks by managing the execution stack and the task queue.

Added: Nov 30, 2025

91. What is a callback function?

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A function passed into another function as an argument, which is then executed inside the outer function.

Added: Nov 30, 2025

92. What is the difference between innerHTML and textContent?

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innerHTML retrieves or sets the content of an element, including HTML markup. textContent retrieves or sets only the text content, without markup.

Added: Nov 30, 2025

93. What is the use of the this keyword?

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this refers to the object it belongs to, which changes based on where and how the function is called.

Added: Nov 30, 2025

94. How can you prevent event bubbling?

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By using the event.stopPropagation() method within the event handler.

Added: Nov 30, 2025

95. What is the difference between the Array methods map and forEach?

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forEach executes a function for each array element and returns undefined. map creates a new array populated with the results of calling a provided function on every element.

Added: Nov 30, 2025

96. What is the difference between the Internet and the World Wide Web (WWW)?

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The Internet is the global network of interconnected computers. The WWW is a collection of documents and resources (web pages) accessed via the Internet.

Added: Nov 30, 2025

97. What are the main components of a URL?

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Protocol (e.g., HTTP), domain name, port (optional), path, and query parameters (optional).

Added: Nov 30, 2025

98. Name the common HTTP request methods.

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GET, POST, PUT, DELETE, PATCH.

Added: Nov 30, 2025

99. What is the difference between HTTP and HTTPS?

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HTTPS is the secure version of HTTP. It uses SSL/TLS encryption to secure communication between the browser and the server.

Added: Nov 30, 2025

100. What is DNS?

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The Domain Name System, which translates human-readable domain names (like google.com) into numerical IP addresses.

Added: Nov 30, 2025

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