Evolution Of Programming Languages

Outline for the Quarter A. B. C. D. E. F.

Evolution of Programming Languages Visual Basic 6.0 Environment Starting a Project Working with Forms Variables and Constants Operators and Functions

Evolution of Programming Languages Lecture

First Generation Languages (1GL)   

Machine Language Uses 1’s and 0’s (binary) Advantages  

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Fast and Efficient Directly understood by the computer

Disadvantages  

Cumbersome – very difficult to learn and use Machine dependent

Second Generation Language (2GL)   

Assembly or Symbolic language Uses mnemonics or very short commands Advantages  

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Less difficult to learn and use (compared to 1GL) Fast and Efficient

Disadvantages   

Still difficult to learn and use Needs to be assembled into machine language Machine dependent (non-portable)

Third Generation Languages (3GL)  

High Level Language Advantages  

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Easier for programmers to learn and use Supports data structures, control structures and structured decomposition Machine-independent (portable)

Disadvantages  

Needs to be compiled to produce object code Program size becomes larger due to overhead code

Fourth Generation Languages (4GL)  

Declarative Language Advantages    

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English-like and non-procedural Easier to learn and use (compared to 3GL) Faster to program due to less coding required Machine-independent (portable)

Disadvantages 

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Not suitable/effective for all programming requirements Inelegant code and difficult to maintain

Programming Paradigms  

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A model or way of thinking about computing A fundamental style of programming regarding how solutions to problems are formulated in a programming language Provides and determines the view that the programmer has of the execution of the program

Imperative Programming   

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Also called procedural programming Oldest and most traditional Declarative description of the problem as a set of rules is provided “How to do” Like a recipe Examples: FORTRAN, Algol, COBOL, Pascal, C

Functional Programming 

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An expression-oriented paradigm that is close to mathematical specification Emphasis on evaluation of expressions Used in academia rather than in commercial software development Examples: Lisp (John McCarthy), Haskell (Simon Peyton-Jones),

Logic Programming  

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Based on logical deduction Declarative description of the problem as a set of rules provided, from which the solutions are then inferred Example: Prolog (Alain Colmerauer)

Object-Oriented Programming (OOP) Uses objects and their interactions to design applications and computer programs  Strongly emphasizes modularity Class – defines the abstract characteristics of a thing (object) Object – an instance in a class Method – ability of an object  Example: Java (Sun Microsystems), C++ (Bjourne Stroustroup), Visual Basic 