Lessons 8-10

Question 1

What is an accelerometer?

Answer 1

A device that measures acceleration, which is a change in speed or direction over time. Sensor detects forces applied to the device e.g. movement, gravity.

Question 2

What is a Blob object?

Answer 2

Provides access to raw binary data.

Question 3

Define a resistive touch screen.

Answer 3

A resistive touch screen is made up of several layers, the topmost of which flexes when
pressed and pushes into the layer underneath. Sensors detect the pressure, which is how
the system knows which part of the screen has been pressed. The touch screens used in
hospitals and restaurants are often resistive.

Question 4

What is civic data?

Answer 4

Location data that’s more easily understood by humans e.g. map or address.

Question 5

What does it mean if something is device-independent?

Answer 5

A program or interface that runs software that produces similar results on a wide variety of hardware.

Question 6

Define a file API.

Answer 6

Used to upload files from a local disk or device’s local storage to a remote server. You can display uploaded files in a Web app. No need for a plug in.

Question 7

What is geodetic data?

Answer 7

Raw location data e.g. latitude and longitude or meters.

Question 8

Define a geolocation API.

Answer 8

Get’s a user’s geographical coordinates (lat and long). Can show a marker on a map.

Question 9

What is local storage?

Answer 9

Persistent data saved to the browser in persistent memory in order to be reopened later on. No expiration date.

Question 10

What does it mean if something is platform-independent?

Answer 10

Means you can use HTML5 to create pages and apps that will run on various different browsers, devices or systems.

Question 11

What does the touchcancel event do?

Answer 11

Triggered when the device launches another app.

Question 12

Define a touch object?

Answer 12

Detects input from touch-enabled devices. Read only objects.

Question 13

What is session storage?

Answer 13

Temporary data kept for only one session until the browser is closed. Erased at the end of a session.

Question 14

What does the Web Hypertext Application Technology

Working Group do?

Answer 14

Created by Mozilla and Opera. Maintains a living HTML specification that includes APIs that were not originally part of the HTML5 spec. e.g. Geolocation, Webworkers, Websockets, File API.

Question 15

Define a webworker API?

Answer 15

Web workers are scripts that run in the background, performing calculations or other actions that allow for a more responsive UI.

Question 16

Define a websocket API?

Answer 16

WebSockets allow you to open a persistent connection between a client and a Web server and exchange text/binary files. Reduces the amount of overhead for real time communication.

Question 17

What does the touchcancel event do?

Answer 17

Triggered when the device launches another app. Helps keep track of active touch objects.

Question 18

Define a FileList.

Answer 18

An array like sequence of File objects including a folder of files from local storage.

Question 19

Define a File Reader?

Answer 19

Provides method to read and display a file.

Question 20

Examples of device-independent apps you can use with HTML5?

Answer 20

GPS, Accelerometer, Camera

Question 21

Which HTML attribute can be used to retrieve data from cameras, camcorders, webcams and microphones?

Answer 21

Capture attribute

Question 22

Define an animation.

Answer 22

The display of a sequence of static images at a fast enough speed to create the
illusion of movement. Regarding the user interface, animation has to do with changing a
display to make it dynamic.

Question 23

What is an AppCache?

Answer 23

AppCache saves a copy of your Web site files locally, in a structured form. The files include HTML, CSS, and JavaScript, along with other resources the site needs to run. After a visitor has visited the site once, subsequent visits will load resources quickly from the local copy rather than waiting on a network connection.

Question 24

What does the Canvas element do?

Answer 24

HTML5’s canvas element is a drawing area under programmatic control. Creates a container for graphics, and uses JavaScript to draw the graphics dynamically. With JavaScript, you can also animate objects by making them move, change scale, and so on.

Question 25

What are cookies?

Answer 25

Cookies are small text files that Web sites save to a computer’s hard disk that contain information about the user and his or her browsing preferences. The content of cookies change as
a user revisits a site and selects different items or changes preferences.

Question 26

Define a data type.

Answer 26

Values in JavaScript appear in special appearances or “dressings”, called data types. Most
often encountered are strings, numbers, undefined, null, symbol, Boolean, object.

Question 27

What does Encapsulate mean in JS?

Answer 27

There might be a style or policy that is supposed to apply to all pages. In such a case, it’s far more convenient and trouble-free to encapsulate the policy in a JavaScript library that knows how to retrieve
the title for itself.

Question 28

What is JSON?

Answer 28

JavaScript Object Notation - to exchange JavaScript objects with a server.

Question 29

What is local storage?

Answer 29

Persistent data saved to the browser in persistent memory in order to be reopened later on. No expiration date.

Question 30

What is parsing?

Answer 30

Parsing is a term used to describe analysis

of complex information into constituent parts.