INF-306 HTML5 Application Development Questions and Answers

Line 26 drop-down: 5

Line 29 drop-down: 8

Line 32 drop-down: 6

The groceries array starts empty. Line 24 runs fruits.shift(), which removes " Apples " from the fruits array. This leaves four fruits, but it does not add anything to groceries. Line 25 calls addVegetables(), which executes groceries = groceries.concat(vegetables);. Since vegetables contains five items, groceries contains 5 items at line 26. Line 27 then executes groceries.shift(), removing the first item from groceries and reducing the count to 4. Line 28 calls addFruits(), which appends the four remaining fruits, increasing the array count to 8; therefore, line 29 is 8. Line 30 executes groceries.pop(), removing the last item and reducing the count to 7. Line 31 executes groceries.shift(), removing the first item and reducing the count to 6. Therefore, line 32 is 6. The addOther() function on line 33 has not executed yet at the line 32 breakpoint. References/topics: JavaScript arrays, debugging breakpoints, concat(), shift(), pop(), push(), array item counting.

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.

pattern → Provides a way to set a regular expression that the value must match

placeholder → Provides a way to set default text that displays until focus is placed in an element

required → Provides a way to set form elements as mandatory

multiple → Provides a way to allow more than one file or email address in a single input

The correct matches are based on standard HTML5 form validation and input-attribute behavior. The pattern attribute defines a regular expression that the input value must satisfy before the form can be submitted successfully. It is commonly used for structured values such as phone numbers, codes, postal formats, or custom identifiers. The placeholder attribute supplies short hint text inside an input field, helping the user understand the expected value before entering data. The required attribute makes a form control mandatory; if the field is empty, constraint validation prevents successful submission. The multiple attribute allows a single input to accept more than one value, specifically for controls such as input type= " file " and input type= " email " , where users may upload multiple files or enter multiple email addresses. The maxlength attribute is not used in these matches because it limits the maximum number of characters that can be entered, but none of the listed descriptions asks for character-length restriction. References/topics: HTML5 form attributes, constraint validation, pattern, placeholder, required, multiple, input validation.

The correct transformation functions are matrix() and skew(). CSS transformations are applied with the transform property and accept transform functions that alter an element’s rendered appearance in two-dimensional or three-dimensional space. MDN defines < transform-function > as a data type representing a transformation that can rotate, resize, distort, or move an element in 2D or 3D space. The matrix() function is valid because it defines a homogeneous two-dimensional transformation matrix, allowing translation, scaling, rotation, and skewing effects to be represented numerically in one function. The skew() function is also valid because it explicitly skews an element on the 2D plane. scroll() is not a CSS transform function; scrolling is handled through overflow behavior or scrolling APIs. move() is also not a valid CSS transform function; the standard transform function for movement is translate(). References/topics: CSS3 transforms, transform property, 2D transformation functions, matrix(), skew().

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< button onclick= " process() " > Process < /button >

< script >

function process()

{

}

< /script >

The button must use the onclick attribute because the required action occurs when the user clicks the button. The plain word click is an event name used in JavaScript event listeners, but it is not the correct inline HTML event-handler attribute. The value of the onclick attribute must be process() because the function must actually be invoked when the click event occurs. Using process alone only references the function name and does not call it in this inline markup context. this.process would attempt to reference a property on the current element, and javascript:process is not the correct handler expression. Inside the < script > block, the correct function declaration is function process(). This defines the named function that the button’s onclick attribute calls. The final structure therefore connects the button event directly to the script function: when the user clicks Process, the browser runs process().

@media screen and (max-width: 480px) {

/* style rules go here */

}

The correct media query is @media screen and (max-width: 480px) {. The requirement says the style rule must apply to screen devices with a width of 480 pixels or less. In CSS media queries, screen identifies the media type, and (max-width: 480px) defines the upper viewport-width limit. This means the enclosed CSS rules apply when the viewport is 480 pixels wide or any smaller value, which is the standard mobile breakpoint behavior. @media screen and (width: 480px) is incorrect because it applies only when the viewport is exactly 480 pixels wide, not below it. @media screen display and (width: 480px) is invalid syntax because display is not used that way in a media query. @media screen-width: 480px is also invalid because it does not follow the required @media media-type and (feature: value) pattern. References/topics: responsive design, CSS media queries, @media, screen media type, max-width, mobile breakpoint styling.

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 method is arc(). In the Canvas 2D API, circles and circular arcs are drawn by creating an arc path on the canvas rendering context. MDN defines CanvasRenderingContext2D.arc() as creating a circular arc centered at (x, y) with a specified radius, start angle, end angle, and drawing direction. To draw a full circle, the common pattern is to call beginPath(), then arc(x, y, radius, 0, 2 * Math.PI), and then use stroke() or fill() to render the path. There is no standard Canvas 2D method named circle(), so option A is invalid. ellipse() can draw ellipses and can mathematically draw a circle if both radii are equal, but the classic and exam-targeted method for drawing a circle is arc(). bezierCurveTo() draws cubic Bézier curves and is used for custom curved paths, not the direct circle primitive. References/topics: Canvas 2D context, arc() method, drawing circles, radians, path rendering.

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

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

Third blank: list= " donateAmount "

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);.

The correct selections are C and D because both declare a function as a property of an object, which is the defining characteristic of a JavaScript method. MDN describes a method as a function associated with an object, or more specifically, an object property whose value is a function. In option C, Score: function() { ... } is object-literal syntax. It defines a property named Score whose value is an executable function, so that property behaves as a method of the object. In option D, this.Score = function() { ... } assigns a function to the Score property of the current object instance. MDN notes that this is commonly used inside object methods to refer to the object the method is attached to. Option B does not declare a method; it calls Score() and assigns the return value. Option A is only an incomplete or ordinary variable declaration and does not create a function-valued object property. References/topics: JavaScript objects, custom classes, methods, function expressions, this.

First blank: < svg width= " 200 " height= " 200 " >

Second blank: < rect width= " 200 " height= " 200 "

Third blank: < circle cx= " 100 " cy= " 100 " r= " 50 "

Fourth blank: < /svg >

The correct solution uses SVG because SVG graphics are vector-based and can scale without pixel distortion when the page or viewport changes. A < canvas > element would require script-based drawing logic, which violates the requirement that JavaScript must not be required. An < img > or < picture > element can display an image, but those options do not define the rectangle and circle directly in markup. The outer container must therefore be < svg width= " 200 " height= " 200 " > . The blue square is created with < rect width= " 200 " height= " 200 " fill= " blue " / > , which produces a rectangle matching the required 200-by-200 dimensions. The centered white circle must use SVG circle geometry: cx= " 100 " and cy= " 100 " place the center at the midpoint of the 200-by-200 square, and r= " 50 " creates the required 50-pixel radius. The final closing tag must be < /svg > .

The correct segment is D: filter: opacity(20%) drop-shadow(8px 8px blue);. The requirement says the image must have 80% transparency, which means only 20% opacity remains visible. The CSS filter property applies graphical effects to rendered elements, including image effects such as opacity adjustment and drop shadows. The opacity() filter function is valid inside filter, and values below 100% make the rendered element more transparent. The drop-shadow() function is also a valid CSS filter function and applies a shadow effect to the input image. Option A changes saturation, not transparency. Option B also changes saturation and incorrectly attempts to use box-shadow() as a filter function. Option C uses opacity(80%), which would produce 80% opacity rather than 80% transparency, and it also uses invalid box-shadow() syntax inside filter. References/topics: CSS filter property, opacity(), drop-shadow(), image effects, transparency.

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display: grid;

grid-template-columns: repeat(6, 1fr);

grid-template-rows: 50px 50px 150px 150px 100px;

grid-gap: 10px 15px;

The correct grid definition starts with display: grid;, which turns the element into a CSS Grid container. To explicitly create six equal-width columns, the correct property is grid-template-columns, and the most efficient value is repeat(6, 1fr). The repeat() function avoids writing 1fr six separate times, while 1fr assigns each column one equal fraction of the available grid width. The five row sizes must be explicitly declared with grid-template-rows, using the exact varied values shown: 50px 50px 150px 150px 100px. This creates five rows with fixed pixel heights. For the spacing requirement, grid-gap: 10px 15px; is the correct shorthand. The first value controls the row gap, so rows are separated by 10px; the second value controls the column gap, so columns are separated by 15px. References/topics: CSS Grid containers, explicit grid tracks, grid-template-columns, grid-template-rows, repeat(), fractional units, grid gaps.

The correct property is clear. In CSS layout, float removes an element from the normal inline flow and positions it to the left or right, allowing following content to wrap beside it. The clear property controls whether an element may be positioned next to preceding floated elements or must be moved below them. MDN defines clear as the property that sets whether an element must be moved below floating elements that precede it. Typical values include left, right, both, and none, allowing the developer to block floats on one or both sides. display controls the formatting behavior of an element, such as block, inline, flex, or grid. float creates the floating behavior; it does not prevent other floats from appearing beside an element. position controls positioning schemes such as static, relative, absolute, fixed, or sticky. Therefore, only clear directly defines the sides where adjacent floating elements are not permitted. References/topics: CSS floats, content flow, clearing floated elements, layout positioning.

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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.

First blank: class Dog extends Pet {

Second blank: super(name, breed);

The correct syntax for deriving one JavaScript class from another is extends, so the derived class declaration must be class Dog extends Pet {. This creates Dog as a subclass of Pet, allowing Dog instances to inherit members defined by the Pet constructor, including name, breed, and the show() function assigned inside the parent constructor. Inside a derived class constructor, super() must be called before using this. The call super(name, breed); invokes the parent Pet constructor and passes the values required to initialize the inherited name and breed properties. Pet(name, breed); is incorrect because a class constructor cannot be invoked like a normal function. Pet.constructor(name, breed); is also incorrect because it does not call the parent constructor for the current instance. After super() runs, the Dog constructor can safely assign subclass-specific properties such as price and gender. References/topics: JavaScript classes, inheritance, extends, derived constructors, super(), custom class creation.