jQuery Quiz Questions 1-10

This article presents a jQuery quiz with answers and explanations, along with a FAQ section covering jQuery fundamentals. Let's rephrase it for better flow and readability while maintaining the original content.

An interactive jQuery quiz is coming soon to the members section, with prizes up for grabs! In the meantime, here are ten jQuery questions that didn't make the cut, but are still valuable for learning or creating your own quiz. Let's test your knowledge!

Question 1:

To which of the following elements can you directly attach jQuery events?

a) object b) embed c) applet d) None of the above

Correct Answer: d) None of the above. jQuery's event system requires DOM elements that support data attachment for event tracking.

Question 2:

True or False: jQuery's event system requires that a DOM element allows attaching data via a property on the element to track and deliver events.

Correct Answer: True

Question 3:

True or False: jQuery provides focusin and focusout events, which are cross-browser equivalents of the focus and blur events and offer bubbling.

Correct Answer: True. focus and blur don't bubble, but jQuery's versions do.

Question 4:

Which code snippet is faster?

a) $('#test1, .test2, .test3, .test4'); b) $('#test1').add('.test2').add('.test3').add('.test4');

Correct Answer: a) $('#test1, .test2, .test3, .test4'); (See jsperf: https://www.php.cn/link/0ee8b1eafadac937e6e03d8866cef9bf and jQuery API: https://www.php.cn/link/e98549a4cb29369fb6dbb48ab0b6e018)

Question 5:

$.grep(array1, function1); This statement does what to the elements in array1 that satisfy function1?

a) Sorts them b) Updates them c) Removes them d) Filters them

Correct Answer: d) Filters them (See jQuery API: https://www.php.cn/link/5d252ff9d89ac9d3420b565f70fccd08)

Question 6:

Given this HTML: <ul id="id1"> <li id="li1">Items 1</li> <li id="li2">Items 2</li> <li id="li3">Items 3</li> </ul>, which jQuery selector returns the same result as $('#id1 li').not($('#li2'));?

a) $('#li2').siblings(); b) $('#id2').siblings('#li2'); c) $('#li2').children(); d) $('#id2').children('#li2');

Correct Answer: a) $('#li2').siblings(); (See JSFiddle: https://www.php.cn/link/41069c81282ba6e19583432967917da9)

Question 7:

The hide() function hides an element by:

a) Setting the "display" inline style to "none". b) Setting the "visibility" inline style to "hidden". c) Horizontally offsetting it off-screen. d) Vertically offsetting it off-screen.

Correct Answer: a) Setting the "display" inline style to "none". (See jQuery API: https://www.php.cn/link/a8feb0f39cfe2d43f62def3b8e657992)

Question 8:

What's the correct way to create a div element with the text "Hello" using jQuery?

a) $("#idName").create("div").text("Hello"); b) $("#idName").create("div").html("Hello"); c) $("idName").css("div").html("Hello"); d) $("#idName").append("Hello"); (Assuming a div with id "idName" already exists)

Correct Answer: d) $("#idName").append("Hello");

Question 9:

Given function function1() { alert(arguments.length); }, what happens when you run function1();?

a) Error: arguments is undefined. b) Error: No arguments provided. c) Alert displays "undefined". d) Alert displays 0.

Correct Answer: b) Error: No arguments provided. (It throws a TypeError because arguments is an array-like object, and accessing its length without arguments causes an error)

Question 10:

$.extend(false, object0, object1, object2); What does this do?

a) Extends object0 with object1 and object2. b) Extends object1 with object0 and object2. c) Extends object2 with object0 and object1. d) Invalid statement.

Correct Answer: a) Extends object0 with object1 and object2. (See jQuery API: https://www.php.cn/link/c22f802f4e2192468fbc9485e31d062f)

Frequently Asked Questions (FAQs) about jQuery:

• What is jQuery? A fast, small, and feature-rich JavaScript library simplifying HTML manipulation, event handling, and animation.

• How to learn jQuery? Start with HTML, CSS, and JavaScript basics, then explore online tutorials, videos, and practice with quizzes.

• Common jQuery functions: .click(), .hide(), .show(), .toggle(), .slideUp(), .slideDown(), .animate(), .fadeIn(), .fadeOut(), .val(), .text(), .html(), .css(), and many more.

• Using jQuery in HTML: Include the jQuery library via a CDN or downloaded file using the <script></script> tag.

• jQuery vs. JavaScript: JavaScript is the language; jQuery is a library built on JavaScript to simplify its use for web development.

• Handling events in jQuery: Use methods like .click(), .dblclick(), .mouseenter(), .mouseleave(), .hover(), .focus(), .blur(), etc.

• AJAX in jQuery: Use jQuery's AJAX methods to load server data asynchronously without page refreshes.

• Creating custom events: Use the .trigger() method.

• Advantages of jQuery: Simplifies HTML traversal, provides concise syntax, supports AJAX, offers built-in effects, and is highly extensible.

• Improving jQuery skills: Practice regularly, work on projects, contribute to open source, and solve coding challenges.

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