Computer Languages [Computing] Computing
Machine Code The only type of program a computer can run is a machine code program. …which looks like this…. Computing
Low Level Languages Low-level languages were developed to make it easier for programmers to write and edit programs. Each machine code instruction is given a mnemonic. Computing
Assembler A Low level language is often called an Assembly Language. A computer cannot run an Assembly Language program. An Assembler converts an Assembly Language program into machine code …then the computer can run it. Computing
Assembly Language It takes many instructions to perform simple tasks. Assembled programs run fast – so needed for Eg. Games. ..but Assembly language programming is still hard work…so…. Computing
High Level Languages A high level language uses recognisable instructions – closer to English! It is easier for programmers to develop and edit high level programs…and this will mean faster program development. …and fewer bugs! Computing
Program Translators A High level language program need to be translated into machine code programs before a computer can run it. Compilers translate high level language source code into executable object code programs…that the computer can run. Interpreters translate each line of a high level language program, running each instruction as it does so. Computing
Examples of High Level Languages FORTRAN – (FORmula TRANslator) used for scientific computing. ALGOL – (ALGOrithmic Language) COBOL (Common Business Orientated Language) used for commercial programming. BASIC – (Beginner’s All-Purpose Symbolic Instruction Code) – a learning language. PASCAL – A well-structured teaching language. C, C+, C++, C* - Evolved from Algol. JAVA – Popular language used for teaching programming …and many, many more….. Computing
High Level Languages Scientific languages would have powerful mathematical functions, and facilities for high precision arithmetic to many decimal places… Commercial languages would have many data processing functions (searching and sorting) and filing facilities. Computing
HTML ..stands for HyperText Markup Language. <body bgcolor=“blue”> <table> <tr> <td><font face=“arial” color=“red”>Ronaldo’s</font></td> <td><font face=“arial” color=“white”>First Page</font></td> </tr> <td><img src=“c:\ronaldo.jpg” align=“right”></img></td> </table> <a href=“page2.htm”>Page 2</a> </body> ..stands for HyperText Markup Language. .... is used to develop web pages. A web page is really a program written in HTML with instructions for the web browser telling it how to display the page. Hyperlinks can be used for navigation between web pages. Multimedia objects can be embedded in a web page. Computing
Special-Purpose Languages Some languages have a special purpose such as… PROLOG – for Artificial Intelligence GASP - for Simulation OCCAM – for parallel processing systems. ADA – for programming embedded systems. Computing
Procedural Languages A sequence of instructions is executed. …use variables, program control (loops etc) and subroutines. Examples : PASCAL, BASIC, FORTRAN, COBOL, ALGOL. Computing
Non-Procedural Languages A set of facts… …and a set of rules, from which information is deduced. Computing
Example (Non-procedural Language) PROLOG Facts : Parent(Tom, Bob) Parent(Pam,Bob) Male(Tom) ..and a set of rules Father(X,Y) := parent(X,Y) Male(X) Brother(X,Y) := parent(Z,X) Parent(Z,Y) …and a query which is answered by applying the facts and rules… ? father(who,Bob) who = Tom Computing
Object Oriented Programming Languages (OOPs) A Class consists of a group of Objects Objects have Properties and Methods. Properties can be set initially or at run-time. Methods are the things the object can do. Examples of OOPs – C#, VB .NET, JAVA, PHP, PYTHON) Computing
Fundamentals of an OOP… A Class is a group of similar Objects. The class of DOGS contains an Object called a COLLIE. A COLLIE has properties and methods. Properties may include: Colour, Breed, No of Legs, etc… Methods may be Bark, Eat, Run, Sit, etc.. LASSIE is an Instance of a COLLIE A Sub-Class may be defined such as HUNTING-DOGS that INHERITS the methods and properties of the Class DOG. Computing
Visual Languages Visual Languages allow the programmer to manipulate objects visually on a form, and set their layout and properties. Often used to create Microsoft Windows Applications. Examples : Visual Basic, Visual C#, Delphi. Computing
ALL programming languages must have… International Standards. Difficult to create because of different hardware and software manufacturers. An unambiguous syntax. There should never be two different ways for a computer to interpret an instruction. Computing