Related Questions

What is the purpose of the jQuery library? — (a) graphic design (b) animation authoring (c) web development (d) database management

Answer: c) web development — specifically DOM traversal and manipulation, event handling, animation, and AJAX in the browser.

Which jQuery method hides an element? — (a) .hideElement() (b) .visibility('hidden') (c) .hide() (d) .disappear()

Answer: c) .hide(). See Effects and Animation.

Which jQuery method displays a hidden element? — (a) .reveal() (b) .show() (c) .display() (d) .visible()

Answer: b) .show().

How do you animate an element to fade out? — (a) .fadeOut() (b) .animateFadeOut() (c) .hide('fade') (d) .fade()

Answer: a) .fadeOut().

Which method hides an element with a sliding animation? — (a) .slideOut() (b) .slideUp() (c) .slideHide() (d) .hideSlide()

Answer: b) .slideUp().

Which call animates an element’s height over 400 milliseconds? — (a) $('el').animate({height: 'toggle'}, 400) (b) $('el').changeHeight('400ms') (c) $('el').heightAnimate(400) (d) $('el').resizeHeight({duration: 400})

Answer: a) $('el').animate({height: 'toggle'}, 400) — height: 'toggle' animates to or from zero; pass a number such as height: 200 for a fixed target.

Which method switches an element between shown and hidden on each call? — (a) .toggle() (b) .fadeIn() (c) .slideUp() (d) .append()

Answer: a) .toggle() — .fadeIn() and .slideUp() also change visibility but only in one direction.

Which method smoothly transitions an element between visible and hidden? — (a) .fadeToggle() (b) .slideDown() (c) .append() (d) .after()

Answer: a) .fadeToggle() — it animates opacity and flips shown/hidden each call; .slideDown() only reveals.

Which jQuery method gets or sets the HTML content of an element? — (a) .html() (b) .content() (c) .innerHTML() (d) .getText()

Answer: a) .html() — innerHTML is a native DOM property, not a jQuery method. See DOM Manipulation.

Which jQuery method gets or sets the text content of an element? — (a) .text() (b) .textContent() (c) .innerText() (d) .getString()

Answer: a) .text().

Which method inserts content at the end of each matched element? — (a) .appendTo() (b) .prependTo() (c) .after() (d) .append()

Answer: d) .append() — .appendTo() is the same insertion with arguments reversed; .after() inserts outside, as a following sibling.

Which method inserts content at the beginning of each matched element? — (a) .prepend() (b) .before() (c) .insertBefore() (d) .startWith()

Answer: a) .prepend() — .before() / .insertBefore() insert outside, as a preceding sibling.

Which method inserts elements immediately before or after an existing element? — (a) .prepend() (b) .after() (c) .wrap() (d) .append()

Answer: b) .after() — with its pair .before(); .prepend() / .append() insert inside the element.

Which jQuery method removes all child nodes of the matched elements? — (a) .empty() (b) .remove() (c) .detach() (d) .unwrap()

Answer: a) .empty() — .remove() deletes the matched elements themselves (with their data and handlers). See DOM Manipulation.

Which jQuery method creates copies of existing elements? — (a) .append() (b) .clone() (c) .replaceWith() (d) .unwrap()

Answer: b) .clone() — pass .clone(true) to also copy event handlers and .data().

Which jQuery method removes a wrapping element from around a selected element? — (a) .unwrap() (b) .remove() (c) .empty() (d) .detach()

Answer: a) .unwrap() — it removes each element’s parent and leaves the element in place.

Which jQuery method changes an element’s inline CSS properties? — (a) .text() (b) .addClass() (c) .css() (d) .attr()

Answer: c) .css() — for styling that lives in the stylesheet, toggle a class with .addClass() / .toggleClass() instead. See CSS, Classes, Attributes and Dimensions.

How do you set the value of an HTML attribute on an element? — (a) .attr() (b) .css() (c) .addClass() (d) .toggleClass()

Answer: a) .attr() — for live form-control state (checked, selected, disabled, current value) use .prop().

What does the .addClass() method do? — (a) removes a class (b) toggles a class on and off (c) adds a class to the selected elements (d) retrieves CSS properties

Answer: c) adds a class to the selected elements — it accepts several space-separated names, or a function.

Which jQuery method toggles a class on and off for the selected elements? — (a) .toggleClass() (b) .removeClass() (c) .addClass() (d) .attr()

Answer: a) .toggleClass() — a second argument forces the direction: .toggleClass('x', isOn).

Which jQuery tool reads or sets an element’s dimensions? — (a) .css() (b) .attr() (c) .addClass() (d) .toggleClass()

Answer: a) .css() works, but the purpose-built methods are .width() / .height(), .innerWidth() / .innerHeight(), and .outerWidth() / .outerHeight() — they return a unitless number and their setters take a plain number.

Which jQuery method selects descendants of an element that match a selector? — (a) .find() (b) .next() (c) .closest() (d) .filter()

Answer: a) .find(). See Traversal and Chaining.

What does the .next() method select? — (a) descendant elements (b) ancestor elements (c) sibling elements (d) elements by visibility

Answer: c) sibling elements — specifically the single immediately following sibling. Use .nextAll() for all following siblings, .siblings() for every sibling.

Which jQuery method refines a set by a condition? — (a) .next() (b) .filter() (c) .closest() (d) .prev()

Answer: b) .filter() — it accepts a selector, an element/set, or a predicate (index, element) ⇒ boolean; its complement is .not().

Which jQuery selector matches elements that are currently hidden? — (a) :visible (b) :hidden (c) .find() (d) .next()

Answer: b) :hidden — note :hidden / :visible are jQuery extensions, not valid CSS, and judge rendered layout (an element with visibility: hidden still counts as visible). See jQuery Selectors.

What is the primary purpose of the jQuery .data() method? — (a) styling elements (b) attaching custom data to an element (c) creating new elements (d) parsing JSON

Answer: b) attaching custom data to an element — the data lives in jQuery’s internal cache, not the DOM. See Element Data and Utility Functions.

Which values can be stored on an element with .data()? — (a) strings and numbers only (b) objects and arrays only (c) strings, numbers, objects, or arrays (d) elements only

Answer: c) strings, numbers, objects, or arrays — .data() accepts any JavaScript value.

How do you retrieve stored data from an element with .data()? — (a) .getData('key') (b) .data('key') (c) .retrieveData('key') (d) .fetch('key')

Answer: b) .data('key') — calling .data() with no argument returns every stored key as an object.

What does the .index() method determine? — (a) the tag name (b) an element’s position among its siblings (c) the number of elements in the DOM (d) the CSS class

Answer: b) an element’s position among its siblings — .index(selectorOrElement) instead reports the position within a given set.

Which method handles user interactions such as clicking and hovering? — (a) .bind() (b) .eventHandler() (c) .interact() (d) .click()

Answer: d) .click() — in modern code, bind with .on('click', handler); the no-argument .click() trigger form is deprecated. See Event Handling.

What is the purpose of the .on() method? — (a) disable all event handling (b) trigger an event programmatically (c) bind one or many events, optionally delegated (d) prevent propagation

Answer: c) bind one or many events, optionally delegated — .on() is the single general-purpose binder: one or more event types, an optional selector argument for delegation, and optional handler data.

Which method stops an event from propagating to parent elements? — (a) .halt() (b) .stopEvent() (c) event.stopPropagation() (d) event.preventDefault()

Answer: c) event.stopPropagation() — called on the event object inside the handler. event.preventDefault() is different: it cancels the default action, not propagation. Returning false from a jQuery handler does both.

What does event.preventDefault() do? — (a) it stops the browser’s default action for the event (following a link, submitting a form, ticking a checkbox) (b) it stops the event bubbling to ancestors (c) it triggers the event automatically (d) it improves event delegation

Answer: a) it stops the browser’s default action for the event — it does not stop other handlers running or the event bubbling (that is event.stopPropagation() / event.stopImmediatePropagation()).

Which method binds events to elements matching a selector, including ones added later? — (a) .register() (b) .bind() (c) .attach() (d) .on()

Answer: d) .on() — $(parent).on('click', 'li', handler) (event delegation); .bind() / .live() / .delegate() never supported this current form or were removed.

Which method handles keyboard events such as a key press? — (a) .click() (b) .hover() (c) .keypress() (d) .submit()

Answer: c) .keypress() — but both the keypress event and this shorthand are deprecated; use .on('keydown', …​) / .on('keyup', …​) and read event.key.

What does AJAX stand for? — (a) Advanced JavaScript and XML (b) Asynchronous JavaScript and XML (c) Automated JavaScript and XHTML (d) Active JavaScript and JSON

Answer: b) Asynchronous JavaScript and XML — the "XML" is historical; responses today are usually JSON. See AJAX.

In $.ajax(), what do options such as type, url, data, and dataType configure? — (a) the server’s response time (b) the browser version (c) the AJAX request itself (d) the user’s IP address

Answer: c) the AJAX request itself — type is a legacy alias for method.

Which shorthand method makes a GET request for JSON data? — (a) $.send() (b) $.fetch() (c) $.getJSON() (d) $.request()

Answer: c) $.getJSON() — it is $.get() with dataType: 'json'; the native global fetch() is unrelated.

What kind of request does $.post() make? — (a) GET (b) POST (c) PUT (d) DELETE

Answer: b) POST.

What is the purpose of the success callback in an AJAX request? — (a) handle errors (b) run after the request completes, success or not (c) send data to the server (d) handle the successful response from the server

Answer: d) handle the successful response from the server — success / error / complete are the legacy style; prefer the jqXHR promise (.done() / .fail() / .then()), Promises/A+ compliant since jQuery 3.

What is the main advantage of shorthand methods such as $.get() and $.post()? — (a) they handle any request type (b) they are more secure (c) they make the code shorter and more readable (d) they give better server performance

Answer: c) they make the code shorter and more readable — they are thin wrappers over $.ajax() with a fixed method / dataType; anything more (headers, timeout, beforeSend) still needs $.ajax().

Which jQuery method is the core of its AJAX functionality? — (a) $.get() (b) $.post() (c) $.getJSON() (d) $.ajax()

Answer: d) $.ajax() — $.get(), $.post(), and $.getJSON() are all shorthands that call it internally.

In the rule .red span { color: red; text-decoration: line-through; }, what is the red class for? — (a) set the background colour (b) mark a crossed-out ("done") item with a line-through (c) change the font size (d) underline the text

Answer: b) mark a crossed-out ("done") item with a line-through — the rule also sets the text colour red, but "line-through" is the part being tested.

What does the click handler on a delete button do? — (a) adds a new list item (b) removes the input field (c) removes the parent <li> from the list (d) toggles the red class

Answer: c) removes the parent <li> from the list — the delegated handler calls .closest('li').remove().

What triggers creation of a new list item? — (a) clicking the "Add to List" button (b) hovering over a list item (c) typing in the input field (d) reloading the page

Answer: a) clicking the "Add to List" button — binding submit on the surrounding form is more robust because it also fires on the Enter key.