High Level Language (HLL)

MULTIFORM
191 FARDIN SAHARIAR SHUVO
182 RABBI-AL-SIFAT
110 MD.NAYMUR RAHMAN SHAKIL
179 NAZMUL HAQUE
174 MD.NOMAN SARKER
116 MD.SHOHAN MOLLA
158 ZUNAET ISLAM BHUIYAN
146 MALIHA JAHAN
115 ARDRA LAILAC
180 SYEDA FATEMA-TUJ-JUMA

Dedicated to
COURSE TEACHER
NUSRAT JAHAN
LECTURER
DEPT OF AIS
UNIVERSITY OF DHAKA

MUI TUMARAY
VHALAPAI 
What da hale U
taking about?
U POM
GANA???
Why
Language
Matters???

Then HOW to bridge between
COMPUTER and HUMAN

What you need
is
Computer understandable
LANGUAGE
Machine Assembly High level

HIGH LEVEL
LANGUAGE
Most updatedone
Most usedone
Most easiestone

High level language
 Machine independent
 Donot require programmers to know
anything about the internal structure of computer
on which high-level language programs will be executed
 Deal with high level coding, enabling the programmers
to write instructions using English words and familiar
mathematical symbols and expressions

Compiler:
• Translator program (software) that
translates a high level language
program into its equivalent machine language
program
• Compiles a set of machine
language instructions for every
program instruction in a high level language

Compiler:
Compiler:input output
High level
language
program
Machine
language
program
Source
program
One to many correspondence
Object
program

Compiler
A Computer Supporting Language L1 and L2
Illustrating the requirement of a separate compiler for each
high level language supported by a computer

Compiler
Compiler for
language L1 on
computer A
Compiler for
language L1 on
computer B
Executed on
computer B
Executed on
computer A
Machine code for P1
that will run on
computer A
Machine code for
P1 that will run on
computer B
Progra
m P1
on high
level
languag
e L1
Same
results
obtain
ed

Syntax Errors
In addition to doing transitional job , compilers also automatically detect and
indicate syntax errors
Syntax errors are typically of following types:
Illegal characters
Illegal combination of characters
Improper sequencing of instructions in a
program
use of undefined variable names
Note: A compiler cannot detect logic errors in a program

Process of removing syntax errors
Edit Source
Program
Compile Source
Program
Start
Syntax
Errors
Detected
?
Generate List of Coded
Error Messages
Generate Object
Program
Stop
No
Yes

Linker:
 A large software, storing all the lines of program code in
a single source file will be:
-> Difficult to work with
-> Difficult to deploy multiple programmers to
cocurrently work towards its development;
-> Any change in the source program would require the
entire source program to be recompiled;

To develop large
software where
the software
consists of
multiple source
program files.
Why modular is
adopted?
CONTINUE……..

Each source program file:
>Can be independently modified
> Compiled to create a corresponding
object program file.
Linker program (software) is used to properly
combine all the object program files (modules).
Creates the final executable program (load
modules).
CONTINUE……..

What is an interpreter?
A high level language translator.
Takes one statement of a high level language
program, translates it into machine language
instructions.
Immediately executes the resulting machine
language instruction.
Complier simply translates the entire source
program into an object program and is not
involved in its execution.

Interpreter
(translates
& executes
statement
–by-
statement)
High-level
Results
Language-
input
Output-Of
Program
Executing
(source
program)

Intermadiate language complier
& Interpreter
New type of complier & interpreter combines the
speed, ease & control of both complier &
interpreter.
Complier first complies the source program to an
intermadiate object program.
Intermadiate object program is not a machine
language code but written in an intermadiate
language that is virtually machine independent.
Interpreter takes intermadiate object
program, converts it into machine language
program & executes it.

Benefits of intermadiate
language complier & interpreter
 Intermadiate object program is in complied form & thus
is not original source code, so safer & easier to share.
 Intermadiate object program is based on a standard
Intermadiate Standard Language (IDL)
 Interpreter can be written for any computer
architecture and operating system providing virtual
machine environment to the executing program.
 Newer interpreter complies intermadiate program, in
memory, into final host machine language program and
executes it.
 This technique is called Just –In-Time (JIT) compilation.

Advantages of High-level
Language
Machine independent;
Easier to learn & use;
Fewer errors during program development;
Lower program preparation cost;
Better documentation;
Easier to maintain.

 Lower execution efficiency
 Less flexibility to control the computer’s
CPU, memory and registers
Limitations of high level
language

 Programming languages are used for simulating real world
problems on computers.
 Much of the real world is made up of objects.
 Essence of OOP is to solve a problem by:
>Identifying the real world objects of the
problem
>Identifying processing required of them
>Creating simulations of objects, process, and
the communications
Object –Oriented programming
languages

 Stands for FORmula TRANslation
 Originally developed by JOHN BACKUS and his team at
IBM followed by several revisions
 Standardized by ANSI as FORTRAN-77 and FORTRAN-90
 Designed for solving scientific & engineering
problems
 Oriented towards solving problems of a mathematical nature
 Popular language amongst scientists and engineers
FORTRAN

C FORTRAN PROGRAM TO COMPUTE
C THE SUM OF 10 NUMBERS
SUM=0
DO 50 | =1. 10
READ (5,10) N
SUM=SUM + N
50 CONTINUE
WRITE(6,20) SUM
10 FORMAT (F6.2)
20 FORMAT (1X, THE SUM OF GIVEN NUMBERS=‘,
F10.2)
STOP
END
A SAMPLE FORTRAN PROGRAMME

 Stands for COmmon Business Oriented Language
 Originally developed started under GRACE HOPPER followed
by conference on data system languages (CODASYL)
 Standardized by ANSI as COBOL-74, COBOL-85 and COBOL-
2002
 Designed for programming business data processing
applications
 Designed to have the appearance and structure of a business
report written in English
COBOL

1. IDENTIFICATION DIVISION- Which specifies the program and it’s
author
2. ENVIRONMENT DIVISION- Which specifies the computer and the
peripheral for compiling and executing the program
3. DATA DIVISION- Which specifies the structure and format of the input
and output data files
4. PROCEDURE DIVISION- Which contains the sequence of operations
that the program has to perform
4 DIVISIONS OF
COBOL PROGRAMME

Self document language program-
programmers will write it but readers will not
require much explanation to understand
Verbose but easy to read-
so many words but comprehensive
COBOL is known as

The person who deals with Business-
Business data processing application
deal with storing, retrieving and processing
corporate accounting information
Accountants- inventory control, billing and
payroll
COBOL is usually for

 Stands for Beginners All-purpose
Symbolic Instructions Code.
 Developed by Professor John Kemeney and Thomas
Kurtz at Darmouth College in the United States
 Standardized by ANSI as BASIC-78
 Designed to be an interactive language and to use an
interpreter instead of an compiler
 Simple to implement learn and use language. Hence it
is a widely use language on personal computers
 Flexible and reasonably powerful language and can be
used for both business and scientific applications.

5 REM PROGRAM TO COMPUTE
6 REM THE SUM OF 10 NUMBERS
10 LET S=0
20 FOR I=1 TO 10
30 READ N
40 LET S=S+N
50 NEXT I
60 PRINT “THE SUM OF GIVEN NUMBERS=”;S
70 DATA 4, 20, 15, 32, 48
80 DATA 12 ,3 ,9 ,14 ,44
90 END;

 Named after the famous seventeenth century French
mathematician blaise pascal
 Developed by Professor Nicklaus Wirth of Federal
Institute of Technology in Zurich
 Encourages programmers to write well
structured, modular programs instills good program
practices
 Recognized as an educational language and is used to
tech programming to beginners
 Suitable for both scientific and business applications
 Has features to manipulate
numbers, vector, matrices, string, set, records, files and

PROGRAME SUMNUMS (INPUT,OUTPUT);
(*PROGRAME TO COMPUTE THE SUM OF 10 NUMBERS*)
(*DECLARATION OF VARIABLES*)
VAR SUM, N:REAL;
VAR I:INTEGER;
(*MAIN PROGRAME LOGIC STARTS HERE*)
BEGIN
SUM:=0;
FOR I:=1 TO 10 DO
BEGIN
READ(N);
SUM:=SUM+N;
END;
WTRITEN(‘THE SUM OF GIVEN NUMBERS=‘,SUM);
END;

Developed in 1972 at AT &T’s Bell laboratories ,
USA by Dennis Ritchie and Brian Kernighan
Standardized by ANSI and ISO as C89, C90, C99
High level programming languages (mainly
machine independence) with the efficiency of an
assembly language
Language of choice of programmers for portable
system software and commercial software
packages like OS, compiler, spreadsheet, word
processor and database management systems

 Simplicity
 Naturalness
 Abstraction
 Efficiency
 Structured Programming Support
 Compactness
 Locality
 Extensibility
 Suitability to its environment
Characteristics of a Good
Programming Language

 Nature of the application
 Familiarity with the language
 Ease of learning the language
 Availability of program development tools
 Execution efficiency
 Features of a good programming language
Factors for Selecting a
Language for Coding an
Application

 Program written in a manner that can be brought into use in other
programs and used whenever needed without rewriting
 Also referred to as subroutine, sub-procedure, or function
 Subprogram call statement contains the name of the subprogram
followed by a list of parameters enclosed within a pair of parentheses
 Intrinsic subprograms (also called built-in-functions) are those
provided with the programming language
 Programmer-written subprograms are written and used
as and when thy are needed
Subprogram

Structure of a
Subprogram
sqrt (x)
Subprogram name Parameter
Subprogram header
Subprogram body
Set of instructions that perform
the intended task

Flow of Control in Case of Subprogram
Calls
subprogram header
subprogram call statement
next statement
subprogram call statement
A subprogram A program that calls
the subprogram twice
Flow of control
8
9
7
6
5
2
3
1
4
next statement
subprogram body

CONCLUSION
HLL :-
 a better & alternative language for the programmers
 overcomes the limitations of LLL
Compiler:-
 a communicator between HLL&LLL
 a detector & indicator of errors
Linker:-
 a tool of taking & fitting multiple OP files
 a load module
Interpreter:-
 a convertor like compiler having some differences
Some examples of HLL at a glance:-
 FORTRAN, COBOL, BASIC, PASCAL, C, C++, C#, Java,
ALGOL, RPG, LISP, SNOBOL, and PROLOG

High Level Language (HLL)

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