Loops and Stuff

3 types of Loop

Nested Loop - loop inside other loops
Conditional Loop - will loop until a specified condition is met
Fixed Loop - loops a set number of times every time

Macro
we can record a set of instructions and get them to repeat by pressing a key stroke (or shortcut which we assign it)

Pre-Defined Functions

int() round() rnd()
commands in programming language, they are already written and we can use them

Compter Languages

Machine Code - the language that computers understand, represented as binary (1,0) and as an electrical charge in the computer system

We program in HLL High Level Languages
+ Must be translated before execution
+ English like language
+ They are portable

LLL - Low Level Languages
- understood by the components and the processor etc etc etc

Translators

+ Compiler - translates and executes each line of code at the same time
+ runs faster, because it gives you an executable file once there are no errors
- not good for debugging, gives you all your errors at once
+ Interpreter - translates and executes each line of code one at a time
+ stop when it finds an error, easier to debug
- slower, must run and translate every time, Interpreter is always running during interpretation

From I onwards

I - Implementation

+ choose which language to write the program in (Visual Basic etc)
+ We simply enter in programming language to a Text Editor

T - Testing
Examples do while age < 0 or age > 100
+ Normal - a test within the boundaries of expected input - 50, 60, 44, 98
+ Extreme - testing on the boundaries of expected input - 0, 100
+ Exceptional - test outwith the boundaries of expected input - 111, "Lion", -1

= Fully Testing is where you carry out tests using each of the three types of test

D - Documentation

+ User Guide - contains how to use the program (after its been installed), controls etc
+ Technical Guide - specifications of the program (requirements) e.g. Minimum Memory Requirements, Minimum Processor Speed, Compatible Operating Systems

E- Evaluation


+ Readability - how easy the program is to read and understand for other programmers

!!!! - Ways to improve readability

- indentation, blank lines, comments, good variable names

+ Fitness for Purpose - Does it do what its supposed to do! (Software Spec.)

+ User Interface - user friendly, easy to use

M - Maintenance

+ Perfective - program does what its supposed to do, but we add new features that weren't in Software Specification
+ Corrective - fix any errors that are not found during testing
+ Adaptive - change the program for different platforms (different processors, OS, Hardware)

Dancing!

The Software Development Process is an Iterative Process


We can remember the stages in the correct order by remembering
A Dance In The Dark Every Monday

The first stage is the Analysis

The document produced at this stage is called Software Specification

This document is a legally binding contract stating what the Software MUST do

The second stage is the Design stage

There are 3 different approaches to this Pseudocode, Structure Diagram and Flow Diagram

The two of these which are Graphical Design Notations are Structure and Flow Diagrams