1. CONCEPTS OF PROGRAMMING LANGUAGES
Week 11
Session by
Manesh T

2. Session Objective Introduction To Computer Program or Language
Levels of Computer languages
Language Processors
Generations of Computer Programming
Types of Programming Languages

3. What is a Programming Language?
A set of rules or instrcutions
A set of rules for converting an algorithm
A language framework for describing computations
Symbols, words, rules of grammar, rules of semantics
Syntax and Semantics
Algorithm
Flowchart
Programs

4. Levels of Programming Languages
class Triangle {
...
float surface()
return b*h/2; }
High-level Language
LOAD r1,b
LOAD r2,h
MUL r1,r2
DIV r1,#2
RET
Assembly Level
Language
Machine level
Language

5. Levels of Programming Languages-Cond

6. Programming Languages (cont’d)
A Machine language program consists of a sequence of zeros and ones.
Each kind of CPU has its own machine language.
Advantages
Fast and efficient
Machine oriented
No translation required
Disadvantages
Not portable
Not programmer friendly

7. Assembly Language
Assembly language programs use mnemonics to represent machine instructions
Each statement in assembly language corresponds to one statement in machine language.
Assembly language programs have the same advantages and disadvantages as machine language programs.
Compare the following machine language and assembly language programs:
8086 Machine language program for
var1 = var1 + var2 ;
8086 Assembly program for
MOV AX , var1
ADD AX , var2
MOV var1 , AX

8. High-Level Programming Languages
A high-level language (HLL) has two primary components
(1) a set of built-in language primitives and grammatical rules
(2) a translator
A HLL language program consists of English-like statements that are governed by a strict syntax.
Advantages
Portable or machine independent
Programmer-friendly
Disadvantages
Not as efficient as low-level languages
Need to be translated
Examples : C, C++, Java, FORTRAN, Visual Basic, and Delphi.

9. Language processors Assembler Compiler Interpreter
converting Assembly to machine
High level language to machine language
Line by line compilation
Debugging is easy
Debugging is faster
Debugging is slow
E.g,: TASM
E.g. TC computer
Eg: BASIC

10. Beyond Fifth Generation Languages
Some talk about
Agent Oriented Programming
Aspect Oriented Programming
Intentional Programming
Natural language programming
Maybe you will invent the next big language

11. Generations of Programming Languages
First Generation Languages
Machine
Second Generation Languag es
Assembly
LOAD x
ADD R1 R2
Third Generation Languages
High-level imperative/object oriented
public Token scan ( ) {
while (currentchar == ‘ ’
|| currentchar == ‘\n’)
{….} }
Fourth Generation Languages
Database
select fname, lname
from employee
where department=‘Sales’
Fifth Generation Languages
Functional Logic
fact n = if n==0 then 1 uncle(X,Y) :- parent(Z,Y), brother(X,Z).
else n*(fact n-1)
Fortran, Pascal, Ada, C, C++, Java, C#
SQL
Prolog

12. Types of Programming Languages
Procedural Programming Languages
Structured Programming Languages
Object-Oriented Programming Languages

13. Programming languages

14. Assembly Language- Features
In this whole problem is solved as a single block.
This is suitable only for small problem.
Difficult to follow and correct errors
           Eg, Assembly Language, BASIC.

15. procedure Programming
Features of procedure oriented Programming:
Large Programs are divided in to small function or Procedure.
Uses Top-Down programming Approach.
Data moves freely from one function to another.
Most of the functions share common data.
Emphasis is given for algorithms.
Disadvantages:
Very difficult identify which data is used by which function.
Error Correction is difficult.
Example: C, Pascal

16. Structured Programming
The program is divided into modules and the modules are then divided into functions.
Each module can work independent of one another.
Example: ADA, Prolog

17. Object oriented programming
The Program is divided into number of small units called Object. The data and function are build around these objects.
The data of the objects can be accessed only by the functions associated with that object.
The functions of one object can access the functions of other object.
Example: C++, Java

18. Object oriented programming

19. Object oriented programming

20. Features of object oriented
Emphasis is given on data rather than procedures.
Problems are divided into objects.
Data structures are designed such that they organize the object.
Data and function are tied together.

21. Possible Questions What are levels of Programming Languages?
Illustrate difference between Assembler and Compiler
What are features of Procedural Languages
What are features of Structural Languages
What are features of Object oriented Languages

22. Thank you!
End of Presentation