INF-306 Questions and Answers

First drop-down: " click " ,

Second drop-down: moveElement,

Third drop-down: false,

The correct event listener syntax is addEventListener(type, listener, useCapture). The first argument must be " click " because the function must run when a button is pressed. The second argument must be moveElement, not moveElement(), because the event listener expects a function reference. Using parentheses would call the function immediately while the page is loading instead of waiting for the user to press a button. The third argument controls the event phase. false means the listener runs during the bubbling phase, which is the normal behavior for button click handling. true would register the listener for the capturing phase instead. Since the code uses document.querySelectorAll( " .item " ), it selects all elements with the class item. The for loop then attaches the same click listener to each selected button individually. This ensures that all four buttons invoke moveElement when clicked.

First drop-down: maxlength=8

Second drop-down: pattern=[A-Za-z0-9]{6,8}

Third drop-down: pattern=[0-9]{3}-[0-9] {2}-[0-9]{3}

The password field needs two constraints. maxlength=8 limits the user to a maximum of eight characters, satisfying the upper length requirement. The pattern=[A-Za-z0-9]{6,8} attribute enforces the complete password rule: only uppercase letters, lowercase letters, and digits are allowed, and the total length must be between six and eight characters. A pattern without {6,8} would not enforce the minimum length, and {1,8} would incorrectly allow passwords shorter than six characters. The Member ID field must follow the visible placeholder format 123-45-678, which is three digits, a hyphen, two digits, another hyphen, and three digits. Therefore, the correct member ID pattern is pattern=[0-9] {3}-[0-9]{2}-[0-9] {3}. The hyphens must be included literally in the pattern because the required format contains them. max=8 is not appropriate for password text length, and size=8 only controls display width, not validation.

First blank: img

Second blank: filter:

Third blank: grayscale(100%)

Fourth blank: blur(8px)

The correct CSS selector is img because the requirement applies the visual effect to gallery images. The correct property is filter:, not transform:, because CSS filters modify the rendered appearance of an element using image-processing effects such as blur, grayscale, opacity, brightness, contrast, and shadows. The filtered sample appears blurred and colorless, so the appropriate filter functions are grayscale(100%) and blur(8px). grayscale(100%) removes all color from the image, converting it to a black-and-white rendering. blur(8px) obscures visual details, making the image difficult to recognize until the protected or authorized state changes the styling. The filter keyword without a colon is not a valid CSS declaration in this context. brightness(40%) and opacity(50%) could further obscure an image, but they are not required to reproduce the shown filtered result. The final declaration is therefore filter: grayscale(100%) blur(8px);.

A CSS flexible box layout is created by applying the display property to a container with either flex or inline-flex. This establishes the element as a flex container and causes its child elements to become flex items. The flex-direction property defines the direction of the main axis and accepts row, row-reverse, column, and column-reverse, allowing items to flow horizontally, vertically, or in reverse order. The align-items property controls how flex items are aligned along the cross axis, with values such as flex-start, flex-end, and center. The direction property controls writing direction and accepts ltr for left-to-right text flow or rtl for right-to-left text flow. Finally, order is applied to individual flex items and accepts an integer value, represented here as “any,” because any numeric order value can be used to rearrange item display order without changing the document source order. References/topics: CSS flexbox, flex containers, flex items, main axis, cross-axis alignment, writing direction, item ordering.

The correct methods are setItem(), removeItem(), and clear(). The HTML5 Web Storage API exposes localStorage as a persistent key-value storage object for the current origin. Data stored in localStorage remains available after page reloads and browser restarts unless it is explicitly removed or cleared. setItem(key, value) stores a value under a named key or updates the value if the key already exists. removeItem(key) deletes one specific key-value pair from storage. clear() removes all key-value pairs from the storage object for that origin. These methods are part of the standard Storage interface used by both localStorage and sessionStorage. write is not a Web Storage method; it is associated with document-writing behavior, not application state storage. cookie is also incorrect because cookies are a separate browser storage mechanism accessed through document.cookie, not a method of localStorage. References/topics: Web Storage API, localStorage, Storage interface, application state, persistent key-value data.

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The correct 2D transformation functions are matrix() and skew(). CSS transformations are applied through the transform property, which accepts transform functions that can move, rotate, scale, skew, or otherwise alter an element visually in two-dimensional or three-dimensional space. MDN describes the < transform-function > type as representing transformations that affect an element’s appearance and can operate in 2D or 3D space. The matrix() function is valid because it defines a homogeneous two-dimensional transformation matrix, allowing multiple transform effects to be represented in a single function. The skew() function is also valid because it distorts an element along the 2D plane. move() is not a CSS transform function; the standard movement function is translate(). scroll() is not a transform function; scrolling is controlled through overflow and scroll APIs. zoom() is not a CSS3 2D transform function. References/topics: CSS3 transforms, transform property, 2D transformation functions, matrix(), skew().

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The correct values are scroll and auto. The CSS overflow property controls what happens when content is too large to fit inside an element’s box. MDN describes overflow as setting the desired behavior when content does not fit inside the element’s padding box. The value overflow: scroll creates a scroll container and displays scrollbars so overflowing content can be reached, even when the scrollbar may not be strictly needed in some rendering environments. The value overflow: auto also creates scrolling behavior when content overflows, but it is conditional: scrollbars appear only when the content exceeds the available box size. hidden is incorrect because it clips overflowing content and hides the excess rather than exposing it through a scrollbar. visible is also incorrect because it allows overflow to render outside the element box and does not create a scroll container. Therefore, when the question asks which settings produce a scrollbar if content overflows, the precise answers are scroll and auto. References/topics: CSS overflow, scroll containers, overflow clipping, automatic scrollbars, layout flow.

The first image has a brown/yellow vintage tone, which indicates the sepia(100%) CSS filter. Sepia converts the image colors into a warm monochrome effect commonly associated with aged photographs. The second image appears faded and washed out while retaining the same general image content, which corresponds to opacity(30%); this makes the image mostly transparent, allowing only 30 percent opacity. The third image shows the original beach image with a visible shadow offset behind it, so the correct filter is drop-shadow(8px 8px 10px black). The first two 8px values define the horizontal and vertical shadow offset, 10px defines the blur radius, and black defines the shadow color. saturate(100%) would leave saturation at its normal level and would not visibly create a special effect. grayscale(100%) would remove color entirely and produce a black-and-white image, which is not shown in the visible rows. References/topics: CSS filter property, image effects, sepia(), opacity(), drop-shadow(), graphical enhancement with CSS.

The correct segment is D because named grid-region layouts are defined with grid-template-areas. This CSS Grid property specifies named grid areas, establishes the cells in the grid, and assigns names to those cells. The syntax requires each row of the grid template to be written as a quoted string, with repeated names indicating that the named area spans multiple columns or rows. In the shown layout, heading spans the entire top row, menu occupies the left column across lower rows, content spans the central area, right occupies the right-side area, and contact spans the bottom content region. Options B and C are incorrect because named grid-area strings do not belong in grid-template-rows or grid-template-columns; those properties define track sizing, not named layout regions. Option A defines explicit column and row sizes but does not define the semantic named areas shown in the mockup. References/topics: CSS Grid, grid containers, named grid areas, grid-template-areas, responsive page layout.

First drop-down: datalist

Second drop-down: vehicles

Third drop-down: < /datalist >

The correct element is < datalist > because the interface requires a text input that provides selectable suggestions while still allowing the user to type. The < input > element uses list= " vehicles " , so it must be connected to a < datalist > element whose id is exactly vehicles. The id cannot be vehicle, because vehicle is already the input element’s own identifier and does not match the value used by the list attribute. The < option > elements inside the datalist define the suggested values: Motorcycle, Truck, Boat, Car, and Bicycle. ul, ol, and li are list-markup elements and do not create input suggestions. select would create a fixed dropdown list, but it would not match the editable input-with-suggestions behavior shown. The closing tag must match the opening datalist element, so the final selection is < /datalist > .

First blank: < legend > Fundraising Campaign < /legend >

Second blank: < progress id= " donate " value= " 30 " max= " 100 " > < /progress >

Third blank: list= " donateAmount "

Responsive layouts use CSS media queries to apply different style rules according to the viewport width or device characteristics. In this scenario, the three wireframes represent desktop, tablet, and mobile breakpoints. The desktop layout should use @media only screen and (min-width: 1025px) because desktop screens are the widest target group and begin above the tablet maximum width. The tablet layout should use @media only screen and (min-width: 481px) and (max-width: 1024px) because it covers the middle range between mobile and desktop. The mobile layout should use @media only screen and (min-width: 285px) and (max-width: 480px) because it targets the smallest viewport range shown in the available choices. The option @media only screen and (max-width: 1025px) and (min-width: 1920px) is logically invalid because a viewport cannot simultaneously be at least 1920 pixels wide and no more than 1025 pixels wide. References/topics: responsive web design, CSS media queries, viewport breakpoints, mobile layout, tablet layout, desktop layout.

The correct positioning method is static. In CSS, position: static is the default positioning behavior for elements. A statically positioned element remains in the normal document flow, meaning it is laid out according to the order of the markup and directly follows preceding elements unless another layout rule changes that flow. MDN defines static positioning as placing the element according to the normal flow of the document, with top, right, bottom, left, and z-index having no effect. This matches the requirement that the element always directly follows the previous default-positioned element and does not depend on viewport characteristics. absolute removes the element from normal flow and positions it relative to a containing block. fixed also removes it from normal flow and positions it relative to the viewport. sticky starts in normal flow but changes behavior relative to a scrolling ancestor when a threshold is crossed. References/topics: CSS positioning, normal document flow, static positioning, viewport-independent layout.

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The valid selections are mouseup, scroll, and blur. A < canvas > element is represented by HTMLCanvasElement, which inherits from HTMLElement; therefore, it participates in the normal DOM event model for element-based interaction. mouseup is valid because it is fired on an Element when a pointing-device button is released while the pointer is over that element, which is a common canvas interaction pattern for drawing tools, games, drag tracking, and selection behavior. scroll is valid as an element event when an element is scrolled, and the HTML event-handler index lists onscroll for HTML elements. blur is also valid because it fires when an element loses focus; a canvas can participate in focus workflows, particularly when made focusable with attributes such as tabindex. play is excluded in this certification context because it is a media playback event associated with HTMLMediaElement behavior, not canvas graphics interaction. datareceived is not a standard HTML canvas or DOM event. References/topics: canvas DOM interaction, element event listeners, mouse events, focus events, scroll events.

The correct answer is D because the layout shown is a named-area CSS Grid layout. The mockup contains five semantic regions: the top header area for the logo and page title, a left-side menu, a central main content area, a right-side additional content area, and a bottom copyright/contact area. In CSS Grid, this type of visual structure is defined with grid-template-areas, where each quoted string represents one grid row and each repeated name represents how far that area spans across columns. In option D, heading spans the full top row, menu occupies the left column across the lower rows, content fills the main center region, right fills the additional content region, and contact spans the bottom row to the right of the menu. Option A only defines row and column sizes and does not name the five content areas. Options B and C are invalid for this purpose because named layout strings do not belong in grid-template-rows or grid-template-columns. References/topics: CSS Grid, grid containers, display: grid, named grid areas, grid-template-areas, page layout construction.