jQuery Quiz Questions 11-20

Following on from jQuery Quiz Questions 1-10 here are questions 11-20. Hopefully you might learn something new about jQuery you didn’t know before. Once more if you find any mistakes please feel free to leave a comment with corrections. Enjoy!

Key Takeaways

• This piece provides a quiz on jQuery, a popular JavaScript library, covering questions 11-20, with each question followed by multiple choice answers and the correct answer.
• The quiz covers various jQuery topics including keypress event handling, function execution, element selection, class addition, element movement, code snippet results, and tag selection.
• The Frequently Asked Questions (FAQs) section explains the purpose of the quiz, preparation tips, topics covered, quiz structure, retake options, strategies for understanding difficult questions, ways to use the quiz for skill improvement, suitability for beginners, use for interview preparation, and other resources for learning jQuery.

Question 11

Which of the following is the correct way to check which key was pressed using jQuery? Answers

• $('#txtValue').keypress(function (event) {
      $('#txtvalue').alert((event.keyCode));
  });
  

• $(‘#txtValue’).keypress(function (event) {
      alert(String.fromCharCode((event.keyCode)));
  });
  

• $(‘#txtValue’).keypress(function (event) {
      alert(fromCharCode((event.keyCode)));
  });
  

• $(‘#txtValue’).keypress(function (event) {
      $(‘#txtvalue’).alert((event.which));
  });
  

Correct Answer

$(‘#txtValue’).keypress(function (event) {
    $(‘#txtvalue’).alert((event.which));
});

API: http://api.jquery.com/keypress/  

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Question 12

Consider the following code snippet:

$('#ul1 li').on('click', function1);
$('#ul1').after('

Last item

‘); Is function1 executed if “lastLi” is clicked? Answers

• yes
• no

Correct Answer no. The .after() function adds the list item outside the UL tag.  

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Question 13

$("ul#myId > li");

What does the above statement return? Answers

• A set of tags whose id is “li”.
• A set of tags which contains class “li”.
• A set of li tags which are children of ul tags that have “myId” class.
• A set of li tags which are children of ul tags that have “myId” id.

Correct Answer A set of li tags which are children of ul tags that have “myId” id.  

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Question 14

Consider the following code snippet:

$('#table1').find('tr').filter(function (index) {
    return index % 3 == 0
}).addClass('firstRowClass');

The result of the above code snippet is ___. Answers

• the rows of table1 at order 3n + 1 (n = 0, 1, 2, …) have class firstRowClass
• the rows of table1 at order 3n (n = 1, 2, …) have class firstRowClass
• all rows of table1 have class firstRowClass
• no rows of table1 have class firstRowClass

Correct Answer the rows of table1 at order 3n + 1 (n = 0, 1, 2, …) have class firstRowClass see answer in action: https://jsfiddle.net/jquery4u/zJW3B/  

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Question 15

Which of the following is the correct way to move an element into another element? Answers

• $('#source').prependTo('#destination');

• $("#source").add("#destination");

• $("#source").html("#destination");

• $("#source").add().html().("#destination");

Correct Answer

$("#source").add("#destination");

 

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Question 16

Consider the following code snippet:

$('span.item').each(function (index) {
    $(this).wrap('Item');
});

Essentially, what does this code snippet do? Answers

• Wraps each span tag that has class item within a li tag.
• Inserts each span tag that has class item into a li tag.
• Inserts Item into each span that has item class.
• Replaces each span tag that has class item with a
• Item
.

Correct Answer Wraps each span tag that has class item within a li tag. see answer in action: https://jsfiddle.net/jquery4u/gv2vq/  

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Question 17

What is the result of the following code snippet?

jQuery.unique([1, 2, 2, 3, 3, 1]);

Answers

• [1, 2, 3].
• [3, 2, 1].
• [1, 1, 2, 2, 3, 3].
• None of the above.

Correct Answer [1, 2, 3]. see answer in action: https://jsfiddle.net/jquery4u/gkJsP/  

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Question 18

Consider the following code snippet:

$('#table1').find('tr').hide().slice(10, 20).show();

What is the result of this code snippet? Answers

• Showing table1’s rows from 11th to 20th.
• Showing table1’s 20 rows from 10th.
• Deleting rows of table1 from 10th to 20th.
• Deleting 20 rows of table1 from 10th onward.

Correct Answer Showing table1’s rows from 11th to 20th. see answer in action: https://jsfiddle.net/jquery4u/MQjer/  

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Question 19

$("div").find("p").andSelf().addClass("border");

The statement adds class border to ___. Answers

• all p tags enclosed in div tag
• all div tags and p tags in div tags
• all div tags
• all p tags

Correct Answer all div tags and p tags in div tags see answer in action: https://jsfiddle.net/jquery4u/eUBup/  

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Question 20

Which of the following statements return(s) a set of p tags that contain “jQuery”? Answers

1. $('p:contains(jQuery)');

2. $('p:contains("jQuery")');

3. $('p:has("jQuery")');

4. 1 and 2
5. 1 and 3

Correct Answer 1 and 2 see answer in action: https://jsfiddle.net/jquery4u/cAnHC/  

Frequently Asked Questions (FAQs) about jQuery Quiz