Chapter 1: Introduction to Programming Language

1. Chapter 1: Introduction to Programming Language CSC425 - Introduction To Computer Programming

2. Generation Of Programming Languages Programming Languages •  A set of rules that telling a computer what to do. •  There are over 200 programming languages in the world. •  Helps we understanding computer. •  We need programming languages • as an alternative to a manual system • diadvantages of manual system: • slow • repetitive • incorrect data/information CSC425 - Introduction To Computer Programming

3. Programming Approach 2 types : Structured and object - oriented. 1. Structured Programming  A methodology in which all program logic is constructed from a combination of three control structures : sequence, selection and repetition (loop)  Program logic is description of the step-by step procedures for a module. CSC425 - Introduction To Computer Programming

4. 2. Object-oriented programming  Packaged the data and procedure into a single unit called an object which can be reused and modified.  Object have classes and subclasses.  Each class contains the characteristics that are unique to objects of that class. data- called attributes or variables procedure - the instructions that tell the data what to do - called operations or method. CSC425 - Introduction To Computer Programming

5. Evaluation Of Programming Languages Machine Language Assembly Language High-Level Language 3GL 4GL 5GL CSC425 - Introduction To Computer Programming

6. Machine Language (1940s – 1950s)  Lowest level of language  Represent data and program instructions as 1s and 0s  The only language that computer directly understand. (Do not require translator)  Not convenient to read and use.  First generation language  Machine - dependent CSC425 - Introduction To Computer Programming

7. Assembly Language (1950s – 1960s)  Second generation language  Developed to replace 1s and 0s use in machine language.  Use mnemonic codes : abbreviations that easy to remember A for Add C for Compare MP for Multiply  Requires a translator to translate the assembly program into machine language ( assembler).  Difficult to learn  Machine-dependent CSC425 - Introduction To Computer Programming

8. High Level Language  Made easy for programmer to develop and maintain program  Machine- independent (can run on may different types of computers)  Have 3 categories : third, fourth and fifth generation  Written in series of English-like words  Must be translated to machine code first. (Use translator) CSC425 - Introduction To Computer Programming

9. 3rd Generation Language (1960 – 1970)  Instruction is written as a series of English-like words.  Often are called procedural languages  Translation is performed using compiler or translator  Example of 3GL programming language: FORTRAN, COBOL and BASIC CSC425 - Introduction To Computer Programming

10. FORTRAN  Stands for FORmula TRANslator  Develop in the late 1950s by team of IBM  Designed for scientific applications  Used most often by scientist, engineers and mathematicians. F O R T R A N Example coding in FORTRAN CSC425 - Introduction To Computer Programming

11. COBOL  Common Business Oriented Language  was developed in the early 1960s  more widely used used for business applications  easy to read, write and maintain BASIC  Was develop in the mid - 1960s by John Kemeny and Thomas Kurtz  Easy to learn and used  Widely used for education and business application. CSC425 - Introduction To Computer Programming

12. 4th Generation Language (1970s – 1980s)  Also uses English-like statements  Non- procedural languages - only to specify what is to be accomplished without explaining how  Coding programs requires less time and effort  Example of programming language : PROLOG, FOCUS, LISP and FORTH CSC425 - Introduction To Computer Programming

13. 5th Generation Language (1990s)  Also called natural language.  A type of query language that allows the user to enter requests that resemble human speech.  Translate human instructions into code the computer understands.  Sometimes referred to as knowledge-based language. CSC425 - Introduction To Computer Programming

14. Example of Natural language Welcome to Inquiry What would you like to know? Do we have hammer #37645? One moment please.. Yes, we have 14 hammer #37645. Do we have 1 box nails #3601? One moment, please. No nails #3601 in stock. CSC425 - Introduction To Computer Programming

15. Language Translator •  Program need to translate because computer only understand machine language. •  Three kind of translator : • - Assembler • - Compiler • - Translator •  Used in assembly language for translate the language to machine language Assembler CSC425 - Introduction To Computer Programming

16. Interpreter •  Translates one program code statement at a time. •  Immediately displays feedback when it finds error. •  Use for Basic Source program INTERPRETER RESULTS Data CSC425 - Introduction To Computer Programming

17. Compiler •  Translating the source code from its original language into machine code. •  Converts the entire source program into machine language at one time •  Use for C and Cobol COMPILER OBJECT PROGRAM RESULTS Source program Program Listing Data CSC425 - Introduction To Computer Programming