Week 7 - PHP Part 1

Question 1

Apache

Answer 1

A type of web server software, different to MySQL which is a database.

Question 2

CMS

Answer 2

Content Management System

Allows for users to create their own website without having to write too much code themselves.

Question 3

What is PHP used for?

Answer 3

It’s used to make websites more interactive as it has access to a number of databases.

Eg; MySQL, Apache etc.

Question 4

What’s the difference between client and server-side with PHP?

Answer 4

Client-side is used for displaying information, and submitting basic forms. Only HTML is seen on the client-side, no PHP.

Server-side is responsible for calculations and data storage.

Question 5

What’s the difference between a loosely and strongly typed programming language?

Answer 5

Strongly typed requires you to determine what the data type is, like in Ruby or C.
Data types can’t be changed after the declaration.

Loosely typed is where you don’t have to declare, however data types can be changed after the declaration.

Question 6

What are numerics?

Answer 6

Floats and integers.

Question 7

What are the 4 ways to display variables?

Answer 7

1. Listing concatenation ( , )
2. Concatenation ( . )
3. Embedded into the quotes of echo.
4. Using escape characters " … "

Question 8

Resource Data Type

Answer 8

A special variable which holds a reference to an external resource like a database (MySQL) or accessing XML files.

Question 9

Reference & Composite Data Types

Answer 9

Special data types which can contain multiple values or complex types of information.

Examples of reference data types include arrays & objects.

Question 10

count()

Answer 10

An inbuilt function into PHP used for checking the number of elements in an array.

Question 11

print r

Answer 11

Prints out all elements and their index.

Question 12

Operator Precedence

Answer 12

Used to manage the order operators are evaluated.

( ) - operator precedence
[ ] - arrays
{ } content blocks/functions

Question 13

Associativity

Answer 13

Used to manage the order operators of equal precedence are executed.

Question 14

Escape Character

Answer 14

" … "

Question 15

What is the client/server architecture with PHP involved?

Answer 15

3 tiers: Client, Processing Tier & Data Storage Tier

• Client: makes HTTPS requests to the processing tier
• Processing Tier: acts as the middle-man between the web browser client and data storage tier. This is implemeneted with PHP.
• Data Storage Tier: stores data into a database and returns requests presented by the processing tier. This is implemeneted with MySQL and other databases.

Question 16

Database

Answer 16

A stored collection of organised and structured information or data, stored electronically or in a computer system/server.

Question 17

What is a web server made up of?

Answer 17

Apache: a web server software used to run the web server (most common oen)

File System: retrieves what format the file is in (.html, .php, both)

PHP Engine: if there’s any PHP found from the file system, it will use this to interpret the PHP code and have it sent back as html to the client-side

Database: such as MySQL, which contains information sometimes needed by PHP for queries of data