INF-306 Practice Questions

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 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.

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 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.

Club Points indicator → < meter >

Order Status group title → < legend >

Choose delivery frequency options → < datalist >

Shipping Information group box → < fieldset >

Displayed shipping information → < output >

The correct semantic elements are selected according to the role each visible form component performs. The Club Points visual indicator represents a scalar measurement within a known range, so it corresponds to < meter > . The bordered Order Status section is a grouped form region, and the caption displayed on the border is a < legend > , which labels a fieldset-style group. The delivery frequency control shows an editable input with selectable predefined values, which is the purpose of < datalist > : it supplies suggested options for an associated input without forcing the user to choose only from the list. The Shipping Information section is visually and semantically a grouped set of related form information, so the surrounding grouping element is < fieldset > . The displayed shipping address is generated or presented as result-style information rather than typed directly in that location, which matches < output > . fieldset groups related controls, legend labels that group, meter displays a bounded measurement, datalist provides input suggestions, and output displays calculated or resulting information.

Media queries support responsive web design and allow different CSS rules to be applied at different screen sizes, device characteristics, or breakpoints. MDN describes media queries as a CSS mechanism for applying styles depending on media type and device or viewport characteristics, including width, height, resolution, and orientation. This is the foundation of responsive design because a page can adapt its layout for phones, tablets, laptops, and desktop displays without changing the HTML document. Breakpoints are the points where the design changes; MDN identifies them as the points where a media query is introduced to improve layout behavior across viewport sizes. Statement A is not generally correct because media queries are primarily a styling and layout mechanism, not a direct performance optimization. They can sometimes help avoid unsuitable layouts, but performance improvement is not their defining purpose. Statement D is incorrect because media queries are CSS rules; they do not execute or dynamically process JavaScript code. References/topics: responsive design, CSS media queries, viewport width, breakpoints, adaptive layout rules.

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First drop-down: navigator.geolocation

Second drop-down: navigator.geolocation

Third drop-down: getCurrentPosition(showLocation)

The correct API object is navigator.geolocation because browser-based geographic location is exposed through the Geolocation API, not through window.location. window.location represents the current page URL and navigation state; it does not provide latitude or longitude. The first selection checks whether the browser supports geolocation by evaluating navigator.geolocation. Inside the block, the same object must be used to request the user’s current position. The correct method is getCurrentPosition(showLocation), which requests the device’s current location and passes a position object to the callback function when the location is available. The callback then reads position.coords.latitude and position.coords.longitude and displays those values with alert(). The alternatives that pass window.location are incorrect because they provide page-location information rather than geographic coordinates. The alternatives that call showLocation(...) directly are also incorrect because the browser must first retrieve the actual position object. References/topics: Geolocation API, navigator.geolocation, getCurrentPosition(), callback functions, latitude and longitude.

The correct causes are insufficient input target size and overlapping input areas. Touch interaction depends on hit testing: the browser or platform determines which element occupies the touched screen coordinate and dispatches the event to that element. If a button’s active area is too small, the user’s finger may visually appear to tap the button while the actual touch coordinate falls outside the actionable target. Microsoft’s touch-target guidance recommends touch targets around 7.5 mm square, approximately 40 × 40 pixels on a 135 PPI display, to support reliable activation. Overlap is also a valid cause because one element can partially cover or compete with another during hit testing; W3C target-size guidance notes that overlapping areas should not be counted as usable target area unless the overlapping controls perform the same action. Event handlers are not the problem by themselves; they are the standard mechanism for detecting user input. “Touch screen not initialized” is not a normal HTML5 application-level cause. References/topics: touch input, event handling, hit testing, target size, overlapping controls.

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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.