1.3.3 Web Technologies

Question 1

What is the purpose of
HTML | CSS | JavaScript

Answer 1

HTML - Used to define the content and structure of a web page. Uses tags.

CSS - Sets the formatting of the website (colours, layout etc.) Enables a consistent look to every page as style sheet is shared.

JavaScript - Adds the interactivity to pages. As well as validation on web forms

Question 2

What three methods can be used to insert CSS into a webpage?

Answer 2

Inline - CSS is added directly into the tag.

Embedded – The CSS is added to the top of each HTML page.

External – All of the CSS is added to an external file and then linked to within each HTML page

Question 3

List the 9 CSS formatting commands that you are expected to know.

Answer 3

background-color
border-color
border-style
border-width
color (font)
font-family
font-size
height
width

Question 4

How is a class identified in HTML / CSS?

Answer 4

Question 5

How is an ID identified in HTML / CSS?

Answer 5

Question 6

What would be the HTML code to create a bullet point list with the values “Hello” and “World” in the list?

Answer 6

Question 7

What would be the HTML code to create a numbered list with the values “Hello” and “World” in the list?

Answer 7

Question 8

What HTML tags are used to embed JavaScript in an HTML page?

Answer 8

Question 9

What HTML tags are used to embed CSS in an HTML page?

Answer 9

Question 10

How would I add a link to the BBC home page using HTML code?

Answer 10

Question 11

How would I add a 100x100 image called “smile.png” to an HTML page and set appropriate alternative text?

Answer 11

Question 12

What is the HTML code to add a form to a page with a text box and a submit button?

Answer 12

Question 13

What is the purpose of the div tag?

Answer 13

To group a section of HTML code together so they can be referred to as one identifier.

Question 14

What are the three largest headings in HTML?

Answer 14

Question 15

What is the purpose of the title tag, and where does it appear?

Answer 15

<title> HELLO WORLD </title>

This would appear in the tab name at the top of the web browser.

Question 16

How do you get JavaScript to show an alert box?

Answer 16

alert(“Message to alert”)

Question 17

How do you write a WHILE loop in JavaScript

Answer 17

Question 18

How do you write an IF statement in JavaScript

Answer 18

Question 19

Define compression

Answer 19

The process of making a file smaller/take up less storage.

Particularly useful when transferring data via the internet

Question 20

Define lossy compression and what types of files it would and wouldn’t be suited to.

Answer 20

Takes away some information from the original - Information is permanently lost in the process (irreversible)

Used on images as some loss of detail is acceptable and unlikely to be noticeable

It is unsuitable for text as the loss of small amounts of information will make it unreadable.

Question 21

Define lossless compression and what types of files it would and wouldn’t be suited to.

Answer 21

Preserves all the information from the original (No data is lost)

Used on files where losing data would not be an option, such as code and written texts.

Question 22

State the two examples of lossless compression

Answer 22

Run Length Encoding

Dictionary Coding

Question 23

Define run-length encoding and what types of scenarios it would and wouldn’t be suited to.

Answer 23

Not suited to natural language

More likely to be used in simple images

Relies on consecutive pieces of data

Each set of consecutive symbols can be represented by the symbol and its number of occurrences e.g. AAAABBBBBCCC could be represented as 4A5B3C

Question 24

Define dictionary coding

Answer 24

Frequently occurring pieces of data or groups of characters are replaced by tokens.

A dictionary is then used to say which tokens match which groups of characters.

When decompressed the dictionary is used to replace the tokens with the original text.

The dictionary needs to be transmitted with the file.