1.3.3 Web Technologies Flashcards
What is the purpose of
HTML | CSS | JavaScript
- 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
Describe and name the three methods that can be used to insert CSS into a webpage
- 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
List the 9 CSS formatting commands that you are expected to know.
- background-color
- border-color
- border-style
- border-width
- color (font)
- font-family
- font-size
- height
- width
How is a class identified in HTML / CSS?
How is an ID identified in HTML / CSS?
What would be the HTML code to create a bullet point list with the values “Hello” and “World” in the list?
What would be the HTML code to create a numbered list with the values “Hello” and “World” in the list?
What HTML tags are used to embed JavaScript in an HTML page?
What HTML tags are used to embed CSS in an HTML page?
How would I add a link to the BBC home page using HTML code?
How would I add a 100x100 image called “smile.png” to an HTML page and set appropriate alternative text?
What is the HTML code to add a form to a page with a text box and a submit button?
What is the purpose of the div tag?
To group a section of HTML code together so they can be referred to as one identifier.
What are the three largest headings in HTML?
What is the purpose of the title tag, and where does it appear?
This would appear in the tab name at the top of the web browser.
How do you get JavaScript to show an alert box?
alert(“Message to alert”)
How do you capture the input from an HTML element using JavaScript?
passcode = document.GetElementById(“nameOfID”)
How do you update an element in an HTML element using JavaScript?
document.GetElementById(“nameOfID”).innerHTML = “Hello World”
How do you write a WHILE loop in JavaScript
How do you write an IF statement in JavaScript
Define compression
- The process of making a file smaller/take up less storage.
- Particularly useful when transferring data via the internet
Define lossy compression and what types of files it would and wouldn’t be suited to.
- 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.
Define lossless compression and what types of files it would and wouldn’t be suited to.
- 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.
- Rewrites data in a more efficient format.
State the two examples of lossless compression
Run Length Encoding
Dictionary Coding
Define run-length encoding and what types of scenarios it would and wouldn’t be suited to.
- 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
Define dictionary coding
- 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.
