An introduction to programming-languages.ppt

An introduction to programming-languages

1. Programming LanguagesProgramming Languages

2. LanguageLanguage
A system of communication.

3. Computer LanguageComputer Language
Means of communication used to
communicate between people and the
computer.

4. Difference between natural language Difference between natural language
and computer languageand computer language
Natural language has a very large
vocabulary whereas computer languages
mostly have a very limited vocabulary.

5. Classification of Computer LanguagesClassification of Computer Languages
Computer Languages
Machine Language Assembly Language High Level Language

6. Machine LanguageMachine Language
Fundamental language understood by
computer.
Also known as Machine Code.
Written as strings of binary 0’s and 1’s.
No translation program is required.
Not really easy to learn.

7. Instruction FormatInstruction Format
Instruction prepared in machine language has 2
parts
 Operation Code: Specifies operation
to be performed.
 Operand: specifies address of operand.
Opcode Operand
(Operation Code) (Address)

8. Advantages of Machine LanguageAdvantages of Machine Language
Programs written in machine language are
very fast to execute as instructions
written in Machine language are directly
understood by CPU and no translation
program is required.

9. Limitations of Machine LanguageLimitations of Machine Language
Machine dependent.
Difficult to program
Error prone.

10. Assembly LanguageAssembly Language
To simplify the program writing process
used in machine language, the numeric
operation codes of Machine language
were substituted by letter
symbols(Mnemonics).

11. MnemonicsMnemonics
It is any kind of mental trick we use to
help us remember.
For example: machine code of 111 can be
interpreted as subtract but it is still easier
for us to remember it as SUB.

12. Addition of two numbersAddition of two numbers
Machine Language
0001100100
…………
…………
…………
…………..
Assembly Language
CLA A
ADD B
STA C
TYP C
HLT

13. Assembly LanguageAssembly Language
The language which substitutes letters
and symbols for the numbers in the
machine language program is called an
ASSEMBLY LANGUAGE or SYMBOLIC
LANGUAGE.

14. Assembler Assembler
The translator program that translates an
assembly code into machine code is called an
Assembler.
Assembly Language
Program
(Source Program)
Assembler
Machine Language
Program
(Object Program)

15. Advantages of Assembly Language over Advantages of Assembly Language over
Machine LanguageMachine Language
Easier to understand and use.
Easy to locate and correct errors.
Easier to modify.
No worry about addresses.

16. Limitations of Assembly LanguageLimitations of Assembly Language
Machine dependent.
Knowledge of hardware required.
Machine and Assembly Languages being
machine dependent are called as Low
Level Languages.

17. High Level Language(HLL)High Level Language(HLL)
High level languages instead of being machine based are
oriented more towards the problem to be solved.
HLL are basically symbolic languages that use English
words and/or mathematical symbols rather than
Mnemonic codes.
HLL are known as Problem Oriented Languages.
Every instruction written in HLL is translated into many
machine language instructions. This is one to many
translation whereas in Assembly Language there is one
to one translation.

18. Compiler Compiler
The translator program that translates the
instructions of HLL into Machine Language is
called Compiler.
High Level Language
Program
(Source Program)
Compiler
Machine Language
Program
(Object Program)

19. InterpreterInterpreter
An Interpreter is a type of translator used for translating HLL into
Machine Code.
It takes one statement of HLL and translates it into a Machine instruction
which is immediately executed.
High Level Language
Program
(Source Program)
Interpreter
Machine Language
Program
(Object Program)

20. Difference between Interpreter and Difference between Interpreter and
a Compilera Compiler
In case of Compiler, whole source program is translated into
equivalent machine language program. The object code thus
obtained is permanently saved for future use. So, repeated
compilation is not necessary whereas in Interpreter no object
code is saved because translation and execution process alternate.
Advantage of an Interpreter over Compiler is that it responses
fast to changes in source program.
Interpreters are easy to write and do not require large memory
space.
Disadvantage of interpreter over compiler is that interpreter is a
time consuming translation method because each statement must
be translated every time it is executed from source program.

21. Assemblers, Interpreters and Compilers
are System Software that translate a
source program into object program and
are known as Language Processors.

22. Advantages of High Level LanguagesAdvantages of High Level Languages
Machine independent.
Easy to learn and use.
Fewer errors.
Easier to maintain.

23. Thank you