Top 50 Jquery Interview Questions with Answers

Jquery Interview Questions with Answers

1. What is jQuery?

a) A programming language
b) A library of JavaScript code
c) A web browser
d) A computer operating system

Answer: b

2. What is the latest version of jQuery?

a) 2.x.x
b) 3.x.x
c) 4.x.x
d) 5.x.x

Answer: b

3. What is the purpose of the jQuery library?

a) To provide an easy way to write JavaScript code
b) To help developers create secure websites
c) To improve website performance
d) To simplify website design

Answer: a

4. How can you include jQuery in your webpage?

a) By downloading it from the jQuery website
b) By linking to it from a CDN
c) By copying and pasting the code from the jQuery website
d) All of the above

Answer: b

5. Which symbol is used to select classes in jQuery?

a) #
b) .
c) :
d) *

Answer: b

6. Which symbol is used to select IDs in jQuery?

a) #
b) .
c) :
d) *

Answer: a

7. Which method is used to hide an element in jQuery?

a) show()
b) hide()
c) remove()
d) clear()

Answer: b

8. Which method is used to animate an element in jQuery?

a) animate()
b) create()
c) transform()
d) modify()

Answer: a

9. Which method is used to add a class to an element in jQuery?

a) addClass()
b) removeClass()
c) toggleClass()
d) All of the above

Answer: a

10. Which method is used to remove a class from an element in jQuery?

a) addClass()
b) removeClass()
c) toggleClass()
d) All of the above

Answer: b

11. What is the purpose of the jQuery .each() method?

a) To loop through an array or object
b) To add elements to a webpage
c) To remove elements from a webpage
d) To animate elements on a webpage

Answer: a

12. Which method is used to get the text content of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: a

13. Which method is used to set the text content of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: a

14. Which method is used to get the HTML content of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: b

15. Which method is used to set the HTML content of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: b

16. Which method is used to get the value of a form element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: c

17. Which method is used to set the value of a form element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: c

18. Which method is used to get the attribute of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: d

19. Which method is used to set the attribute of an element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: d

20. Which method is used to get the parent element of an element in jQuery?

a) parent()
b) child()
c) sibling()
d) ancestor()

Answer: a

21. Which method is used to get the children elements of an element in jQuery?

a) parent()
b) child()
c) sibling()
d) ancestor()

Answer: b

22. Which method is used to get the sibling elements of an element in jQuery?

a) parent()
b) child()
c) sibling()
d) ancestor()

Answer: c

23. What is the difference between the .parent() method and the .parents() method in jQuery?

a) The .parent() method only returns the immediate parent element, while the .parents() method returns all ancestor elements.
b) The .parent() method only returns the first parent element, while the .parents() method returns all parent elements.
c) The .parent() method only returns elements with a specific class, while the .parents() method returns all elements.
d) The .parent() method only returns elements with a specific ID, while the .parents() method returns all elements.

Answer: a

24. Which method is used to filter elements in a selection in jQuery?

a) filter()
b) map()
c) reduce()
d) sort()

Answer: a

25. Which method is used to find elements in a selection in jQuery?

a) filter()
b) map()
c) reduce()
d) find()

Answer: d

26. Which method is used to add elements to a selection in jQuery?

a) add()
b) append()
c) prepend()
d) replace()

Answer: a

27. Which method is used to remove elements from a selection in jQuery?

a) remove()
b) detach()
c) clear()
d) erase()

Answer: a

28. Which method is used to bind an event handler to an element in jQuery?

a) on()
b) click()
c) bind()
d) attach()

Answer: a

29. Which method is used to trigger an event handler in jQuery?

a) trigger()
b) fire()
c) activate()
d) start()

Answer: a

30. What is the difference between the .click() method and the .on(‘click’) method in jQuery?

a) The .click() method can only be used on anchor elements, while the .on() method can be used on any element.
b) The .click() method can only be used once on an element, while the .on() method can be used multiple times.
c) The .click() method is shorthand for the .on(‘click’) method.
d) The .click() method cannot be used on form elements, while the .on() method can.

Answer: c

31. Which method is used to stop the default behavior of an event in jQuery?

a) stop()
b) preventDefault()
c) cancel()
d) halt()

Answer: b

32. Which method is used to stop an event from bubbling up the event chain in jQuery?

a) stopPropagation()
b) cancelBubble()
c) endPropagation()
d) terminateBubble()

Answer: a

33. Which method is used to delay the execution of code in jQuery?

a) delay()
b) pause()
c) hold()
d) wait()

Answer: a

34. Which method is used to animate the opacity of an element in jQuery?

a) fadeIn()/fadeOut()
b) show()/hide()
c) animate()
d) slideDown()/slideUp()

Answer: a

35. Which method is used to animate the height of an element in jQuery?

a) fadeIn()/fadeOut()
b) show()/hide()
c) animate()
d) slideDown()/slideUp()

Answer: d

36. Which method is used to animate the width of an element in jQuery?

a) fadeIn()/fadeOut()
b) show()/hide()
c) animate()
d) slideDown()/slideUp()

Answer: c

37. Which method is used to create a new element in jQuery?

a) create()
b) append()
c) prepend()
d) html()

Answer: a

38. Which method is used to add content to an element in jQuery?

a) create()
b) append()
c) prepend()
d) html()

Answer: d

39. Which method is used to remove all child elements from an element in jQuery?

a) empty()
b) remove()
c) detach()
d) erase()

Answer: a

40. Which method is used to replace an element with new content in jQuery?

a) replace()
b) replaceWith()
c) swap()
d) exchange()

Answer: b

41. Which method is used to serialize a form in jQuery?

a) form()
b) serialize()
c) submit()
d) serializeForm()

Answer: b

42. Which method is used to load data from a server and place it into an element in jQuery?

a) ajax()
b) load()
c) get()
d) fetch()

Answer: b

43. Which method is used to send data to a server in jQuery?

a) ajax()
b) load()
c) get()
d) post()

Answer: d

44. Which method is used to set a timer in jQuery?

a) setTimeout()
b) setInterval()
c) delay()
d) pause()

Answer: b

45. Which method is used to stop a timer in jQuery?

a) clearTimeout()
b) clearInterval()
c) stopInterval()
d) pauseInterval()

Answer: b

46. Which method is used to set the content of an input element in jQuery?

a) text()
b) html()
c) val()
d) attr()

Answer: c

47. Which method is used to disable an input element in jQuery?

a) enable()
b) disable()
c) readonly()
d) writable()

Answer: b

48. Which method is used to select elements based on their position in a selection in jQuery?

a) eq()
b) nth()
c) position()
d) order()

Answer: a

49. Which method is used to get the height of an element in jQuery?

a) height()
b) width()
c) length()
d) size()

Answer: a

50. Which method is used to get the width of an element in jQuery?

a) height()
b) width()
c) length()
d) size()

Answer: b

How to Use add-remove CSS classes in jQuery?

So in this blog, we’re going to learn that Use add-remove CSS classes in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js and define-

Additional CSS classes can be added to an element via addClass() For instance, add the class .fancy-link to all anchor tags. Note that you *do not* add a dot in front of the class name here.

$(“a”).addClass(“fancy-link”);

You can also add multiple classes at once.

  $(“p:first”).addClass(“large emphasize”);

To attach a class based on the index of the element in your selected set of elements, you can use a callback function.

$(“li li”).addClass(function(index) {
// This adds classes .item-0, .item-1, … to the list’s sub-items.
$(this).addClass(“item-” + index);
});

You can even use two parameters for the callback function, the index and the current class of the element.

$(“div”).addClass(function(index, currentClasses) {
console.log(currentClasses); // String containing all classes

// Add .red-box if the current classes contain "dummy"
if (currentClasses.indexOf("dummy") !== -1) {
  return "red-box";
}

});

CSS classes in jQuery without js
 CSS classes in jQuery with js
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How to Use change CSS styles in jQuery?

So in this blog, we’re going to learn that How to Use change CSS styles in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js and define-

To retrieve or set the value of a CSS property, you can use css(). This works similar to attr() and prop(): pass one argument to read or two arguments to set a new value. For instance, you can achieve the same as with hide() like this:

 $(“p:first”).css(“display”, “none”);

You can change any CSS property in this simple way.

  redBox.css(“background-color”, “#AA5500”);

  $(“p”).css(“font-size”, “20px”);

You can even change the value of a property relative to its previous value

redBox.css(“width”, “+=20px”);
redBox.css(“height”, “-=20px”);

Also, you can retrieve multiple values by passing an array as the argument

 var properties = $(“p”).css([“font-size”, “line-height”, “color”]);

You can see that in the Developer Tools (F12 in browser) in the Inspector tab.

redBox.css(“user-select”, function() {
// [some logic here…]
return “none”;
});

Use change CSS styles in jQuery
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How to Use image-slideshow in jQuery?

So in this blog, we’re going to learn that How to Use an image-slideshow in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js and define-

Select the <img> inside the gallery to manipulate it later Now, Initialize an array of all images for 

the gallery we want to cycle through all images we have and show one after the other in our 

gallery. For this, we create a variable i: the index of the image we want to currently show. setInterval will call whatever code is inside the callback function every  2 seconds. This way, 

we can change the shown image every 2 seconds.

 

Use image-slideshow in jQuery
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How to Use Change Attributes Properties in jQuery?

So in this blog, we’re going to learn that How to Use Change Attributes Properties in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js and define-

In this main.js To read the current value of an attribute, use attr() with only one argument: the name of the attribute you want to read. after that Retrieve the value of the href attribute of the “<a>” tag This is logged into the console. To see it, press F12 in Firefox/Chrome to open the Developer Tools and click on the Console tab.

Change Attributes Properties in jQuery

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How to Use Removing elements in jQuery?

So in this blog, we’re going to learn that How to Use Removing elements in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js.

Removing elements in jQuery
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How to Use Replacing Elements and Content using jQuery?

So in this blog, we’re going to learn that How to Use Replacing Elements and Content using jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js.

Replacing Elements and Content using jQuery
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How to Use adding-elements in jQuery?

So in this blog, we’re going to learn that How to Use Adding elements in jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js.

Use adding-elements in jQuery
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How to Use jQuery Filters to Specify Your Element Selections?

So in this blog, we’re going to learn that How to Use jQuery Filters to Specify Your Element Selections?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js.

jQuery Filters to Specify Your Element Selections
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How to use Traversing DOM Elements using jQuery?

So in this blog, we’re going to learn that How to use Traversing DOM Elements using jQuery?

So let’s go ahead and do that for first in index.html, with help of style.css & main.js.

Traversing DOM Elements using jQuery
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