INF-306 Sample Questions Answers

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: type

Second blank: pattern

Third blank: required

The first blank must be type because the question requires the input data type to be text, producing type= " text " . The second blank must be pattern because [0-9]{5} is a regular expression that permits exactly five numeric digits. The third blank must be required because the postal code field must be mandatory before the form can be submitted.

The correct answers are A and C because background-size: contain and background-size: cover are the CSS values that scale a background image in response to the size of the element or viewport. contain scales the background image as large as possible while preserving the entire image inside the background area. This prevents cropping and maintains the image’s aspect ratio, although empty space may appear if the container and image proportions differ. cover also preserves the aspect ratio, but scales the image until the entire background area is filled; this may crop part of the image, but it prevents empty space. Both values are commonly used in responsive design because the image automatically recalculates its rendered size as the page or element changes dimensions. initial resets the property to its default behavior and does not intentionally create responsive scaling. auto uses the image’s intrinsic dimensions or proportional automatic sizing, so it does not reliably adjust the graphic to different screen sizes in the way required. References/topics: responsive design, CSS background images, background-size, contain, cover, viewport-based scaling.

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First drop-down: four

Second drop-down: maxlength

Third drop-down: email, password, and phone

The form contains four user-entry input elements: email, password, confirm password, and phone. Since the requirements state that all fields must be completed, the required attribute must be applied to all four inputs. The password field must prevent entries longer than eight characters, so the correct length-control attribute is maxlength, not max; max applies to numeric/date-style value ranges, while maxlength limits character count in text-style inputs. The phone field also benefits from maxlength because its placeholder format has a fixed visible structure. Finally, completed pattern attributes are needed for email, password, and phone because each has a required format rule: the email must match the placeholder-style address format, the password must use only letters and numbers, and the phone number must follow the placeholder format such as 123-45-678. The title attribute should accompany these patterns to produce meaningful browser validation messages.

The correct selections are B and C because both define a function as a member of an object context, which is the essential JavaScript pattern for declaring a method. MDN defines a method as a function that is a property of an object. It also shows that a function expression can be assigned to a variable or property and then invoked later. In option B, Score: function() { ... } represents an object-literal method property. This pattern is commonly used when defining custom objects, prototypes, configuration objects, or class-like structures in JavaScript. In option C, this.Score = function() { ... } assigns a function to the current object instance, creating an instance method that can be called through that object. Option A does not declare a method; as written, it is only an invalid or incomplete variable assignment and does not use the function keyword or method syntax. Option D invokes Score() and assigns its return value to a; it calls a function rather than declaring a method. References/topics: JavaScript custom classes, object members, function expressions, object-literal methods, instance methods.

The correct answer is A because the code at line 03 creates an object by calling a constructor function with the new keyword. A constructor function must be declared with the same identifier used in the new Student( " David " , " Hamilton " ) expression. Inside the constructor, instance members should be assigned through this, because this refers to the newly created object. Option A correctly initializes this.firstname, this.lastname, and this.fullname, so beststudent.fullname is available at line 04 and evaluates to " David Hamilton " . Option B is invalid JavaScript syntax because var student(firstName, lastName) is not a valid function declaration. Option C is also invalid syntax for the same reason: var Student(firstname, lastname) cannot declare a constructor. Option D uses a valid function declaration, but it assigns firstname, lastname, and fullname without this, which creates or references non-encapsulated variables rather than properties of the constructed object. References/topics: JavaScript constructor functions, new keyword, object instance properties, this, custom classes.

First drop-down: flex boxes

Second drop-down: background-size

Third drop-down: cover

The correct layout mechanism is responsive flex boxes because the content changes from a vertical mobile arrangement to a wider multi-column layout as space becomes available. Flexbox supports this behavior naturally through flexible item sizing and wrapping, often without needing explicit media queries for every screen size. The header image must fill its visible header region on both mobile and desktop. The correct CSS property for controlling how a background image scales inside its container is background-size. The correct value is cover, because background-size: cover scales the image so that the entire container is covered while preserving the image’s aspect ratio. This prevents distortion, although some cropping can occur when the image and container have different aspect ratios. contain would preserve the full image but may leave empty space. auto would use the image’s intrinsic size and would not reliably fill the header area. background-attachment, background-clip, and background-repeat do not control image scaling.

The SVG image is built from three filled polygon faces, one white ellipse, and two white diagonal line segments. The three < polygon > elements define the black cube faces by connecting multiple coordinate points. The small white oval on the top face must be an < ellipse > because the markup uses cx, cy, rx, and ry; these attributes define an ellipse center point and horizontal/vertical radii. The diagonal marks on the left and right faces are straight segments, so they must use the SVG < line > element. A line is defined with starting coordinates x1, y1 and ending coordinates x2, y2. The first diagonal runs from the bottom point (200,365) to the upper-left point (50,100). The second diagonal must mirror it on the right side, so it starts at (200,365) and ends at (350,100). Therefore, the final coordinate selection is x2= " 350 " y2= " 100 " . References/topics: SVG shapes, < polygon > , < ellipse > , < line > , coordinate-based vector drawing, SVG markup construction.

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 correct features are saving temporary authentication tokens and passing form data to a confirmation page. sessionStorage provides a storage area scoped to the current origin and browser tab, and its data is retained only for the duration of the page session. That makes it appropriate for short-lived application state that must survive page reloads or navigation within the same workflow, but should not remain permanently available after the session ends. Passing form data from an entry page to a confirmation page is a classic session-scoped use case because the data is needed briefly during a multi-page transaction. Temporary authentication tokens can also fit the session-storage model when the token should be tied to the active browser session rather than persisted across future visits. Customized UI/UX settings usually need to persist across sessions, so localStorage or server-side user preferences are more appropriate. Game progress saved for future use is also persistent state, not session-only state. Passing data to a function is ordinary JavaScript memory usage and does not require Web Storage. References/topics: application state management, Web Storage API, sessionStorage, temporary workflow data, session-scoped tokens.

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The correct setting is overflow: auto;. The requirement is precise: the text must remain inside the element’s border, must not be lost, and scrollbars should not appear unless they are needed. overflow: auto satisfies all three requirements because it clips overflowing content to the element’s box and creates scrollbars only when the content actually exceeds the available space. This preserves access to all text while avoiding unnecessary horizontal or vertical scrollbars when the content fits. overflow: hidden is incorrect because it clips the overflowing text and provides no scrolling mechanism, meaning some content may become inaccessible. overflow: visible is incorrect because the extra text can flow outside the element boundary, violating the requirement to keep content inside the border. overflow: scroll is close but not optimal because it forces scrollbars even when they are not required, which directly conflicts with the instruction to avoid unneeded scrollbars. References/topics: CSS overflow, scroll containers, text containment, content clipping, layout flow.

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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.

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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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 "

The correct answer is D because the pattern attribute requires the exact structure defined by the regular expression [a-zA-Z]{4}-[0-9] {2}-[0-9]{4}-[a-zA-Z] {4}. The first group, [a-zA-Z]{4}, requires exactly four alphabetic characters. The second group, [0-9] {2}, requires exactly two numeric digits. The third group, [0-9]{4}, requires exactly four numeric digits. The final group, [a-zA-Z] {4}, requires exactly four alphabetic characters. Hyphens must appear between each group. Option D, kukX-34-4938-WJDF, satisfies every part: kukX is four letters, 34 is two digits, 4938 is four digits, and WJDF is four letters. Option A fails because Uhj6 contains a digit in the final letter-only group. Option B fails because y7Ts contains a digit in the first group and A3 is not two digits. Option C fails because 23h contains a letter and breaks the two-digit group. References/topics: HTML5 input validation, pattern attribute, regular expressions, form constraint validation.

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The valid filter declarations are filter: opacity(25%) and filter: drop-shadow(16px 16px 16px red). The CSS filter property applies graphical effects to an element, commonly including image rendering effects such as blur, contrast, color shifts, transparency, and shadows. opacity(25%) is a valid filter function because filter opacity accepts a percentage or number to control the rendered transparency of the element. drop-shadow(16px 16px 16px red) is also valid because drop-shadow() is a CSS filter function, and MDN shows that it accepts two or three length values plus an optional color. box-shadow(...) is invalid in this context because box-shadow is a standalone CSS property, not a filter function; MDN explicitly distinguishes drop-shadow() from the box-shadow property. blur(25deg) is invalid because blur uses a length value such as pixels, not an angular value such as degrees. References/topics: CSS filter property, image effects, opacity filter, drop-shadow filter, valid filter-function syntax.

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