G043: Lecture 12 Basics of Software Development Mr C Johnston ICT Teacher

Session Objectives Have an understanding of the basics of software development

Programming When software is being developed it will end up being coded within a computer programming language. Languages can be spilt into low, intermediate and high level, Position Jan 2010Programming LanguageRatings Jan 2010Type 1Java17.482%H 2C16.215%I 3PHP10.071%H 4C %H 5(Visual) Basic7.354%H 6C#5.767%H 7Python4.453%H 8Perl3.562%H 9JavaScript2.707%H 10Ruby2.474%H 11Delphi2.392%H Source: (Jan 2010), “Tiobe index”, Accessed http://

Basics of Software Development Programs are made up of instructions written in the language, Instructions are followed in sequence to produced a desired outcome, Each language of which has its own set of rules and syntax, When developing software no matter which language being used you need to use: The data which will be input The outputs from the system How the data will be stored How the processing of data will be controlled The efficiency of the program which relates to the precision in framing instructions

Writing about data which will be inputted…..

Writing about data which will be outputted…..

Writing about how data will be stored

Understanding Data Structures Char Stores a single character e.g. VAR X AS Char X = a String Stores a number of characters e.g. VAR X AS String Length 5 X = ab12? Array Stores a column of data of the same data type e.g. VAR X As Array X 1 = ab12? X 2 = qwew! X 3 = re43$ Record Stores a several columns of data - could be different types e.g. VAR X As Record X 1 = ab12?, 12.3, F X 2 = qwew!, 23.5, F X 3 = re43$, 43.5, T

Writing about how processing of data is controlled

Writing about efficiency of programming instructions

Common Instructions Declaring variables (a basic storage bin) Setting data types (numerical, text, Boolean) Defining data structures (string, array, record, files) Using selection (IF statements) Using sequence (Loops – repeats until a condition is met) Manipulation of variables (changing them) Modularity (Modules, Functions, Sub routines, Procedures - splitting code up into bits)

Illustration Through Annotation Inputs entering routine as variables from another routine Selection and iteration - efficient loop saves code, could be a case statement instead of nested if but as only three conditions Module begins – one of Many within the program Module ends Variable declared for use in function Data Output – passed onto next routine

The Task Explain the basics of computer programming including languages used and some of the common instructions You need to make notes about some of the development steps on slide 4, The notes need to explain each step, A diagram of illustrated code will help you show some of the techniques used.