Principles of Software Development 1 Principles Of Software Design and Development Types of language / Choosing a language

Principles of Software Development 2 Aims Discussion into programming Discussion into what types of languages exists Gain knowledge into why do we have different types of languages

Principles of Software Development 3 Discussion into Programming What is programming The processor can only understand instructions in the form of binary code (ones and zeros) For Example: (letter A) Most humans however can not understand binary code, therefore most languages are written using symbolic languages (English like statements) – this make it easier for humans to understand.

Principles of Software Development 4 Types of languages There are many different types of programming languages, which have been developed over the years, each of which have there own features, some of which are listed below: –Procedural programming –Object-orientated programming –Visual programming –Mark-up languages –Script languages

Principles of Software Development 5 Procedural programming All tasks that the computer is required to undertake are broken up into subroutines or functions These subroutines/functions are called within a main program Usually code is executed in a linear order from the first statement to the second and so forth Example: C, C++, Fortran, Pascal, and Basic.

Principles of Software Development 6 Object-oriented programming In Object-oriented programming (OOP) a program is broken down into objects as appose to procedures. Each object is capable of receiving messages, processing data, and sending messages to other objects. Programming techniques may include features such as encapsulation, modularity, polymorphism, and inheritance. Example: VB.net, Java..

Principles of Software Development 7 Visual programming (Event Driven) It has features to enable you to drag and drop various objects onto a form i.e. buttons, menus, labels and textboxes etc It is a visual way of programming, objects can be manipulated in some way through the use of code. Each object, for example a text box has a list of its own properties which can be set through a properties window or through code Each object has a list of methods which can also be used to aid the programmer Example: Visual Basic

Principles of Software Development 8 Mark-up languages This is not a true programming language as they do not contain instructions to control the flow of a program i.e. structures or loops They only give instructions to control format and layout of a computer file (web page). When a web page needs to carry out programming functions like making a decision, Script has to be used. Example: HTML (Hyper text mark-up language)

Principles of Software Development 9 Script languages Scripting languages are nearly always embedded in the application with which they are associated. Most Scripts are often used for client-side web development Enables an application to carry out programming functions like making a decision Example: JavaScript

Principles of Software Development 10 Things to consider Different categories and the examples given within them are not mutually exclusive. Many modem programming languages combine features of all the different categories. For example modem Visual Basic.Net is known as a visual programming environment as well as an object oriented environment

Principles of Software Development 11 Why do we have different types of languages Each programming language has been created to meet a specific need Examples are given below: Basic and Pascal were created originally to allow the non scientific students to learn how to program. Visual Basic was derived from Basic, therefore was designed to be easy to learn and use. The other specific need was to develop interfaces fast. COBOL (COmmon Business-Oriented Language) was the first widely-used high-level programming language for business applications. This was written to enable businesses like finance, and government to develop computer applications.

Principles of Software Development 12 Why do we have different types of languages Cont. OOP – This came about due to hardware and software became increasingly complex. As a direct result of this the software’s quality was often compromised to get it onto the market and to meet the required needs. OOP was deployed as an attempt to address this problem by prompting discrete units of programming logic and re-usability in software. JavaScript – was developed to add functionality to embedded applications like websites. It was designed to look like Java, but be easier for non-programmers to work with.

Principles of Software Development 13 Conclusion Discussed programming Discussed what types of languages exists Gained knowledge into why do we have different types of languages