Lecture 01 Flashcards
Scientific applications
Large numbers of floating-point computations; use of arrays
Fortran (Formula Translating System, IBM)
Business applications
Produce reports, use decimal numbers and characters
COBOL (COmmon Business-Oriented Language)
Artificial intelligence
Symbols rather than numbers manipulated; use of linked lists
LISP (LISt Processing)
Systems programming
Need efficiency because of continuous use
C
Web Software
eclectic collection languages: markup HTML, scripting PHP, general purpose Java
Machine languages
Hardware implemented languages.
Set of the instructions of a processor.
Machine code is usually written in hexdecimal numbers.
Assembly languages
machine codes are wrapped with alphanumeric symbols so that the instructions are more
readable.
High-level languages:
languages that are machine independent
System programming languages:
differ from application
programming languages
web authoring, database,
or scientific computing
for I/O, memory processor, drivers, OS
Scripting languages
transform a large amount of regular textual information.
Python, PHP, etc
Domain-specific languages:
unlike general purpose
languages, they are used in highly special-purpose
areas only,
e.g., PostScript - vector graphics
Procedural
program is built from one or more procedures
Functional
Main means of making computations is by applying functions to given parameters like Haskell, LISP…
Logic
Rule-based like ProLog
Imperative languages:
computing tasks are defined as sequences of commands
(statements) for the computer to perform.
program in such language tells computer what to do step-by step
Declarative languages
in which programs describe their desired results without explicitly
listing commands or steps that must be performed.
– functional and logical programming languages belong to this category.
Most Influential Languages
FORTAN - Scientific Computing.
COBOL - Business Data Processing.
Algol - Overcome problems of FORTRAN.
Pascal - Descendant of Algol intended to be more efficient and to compete with Fortran as General Purpose Language.
Fortran
Fortran (Formula Translation) is first well-known high level language.
Fortran Development Goals
The developmemnt goals:
To lower costs involved with programming and debugging.
To compete with hand-coded assembly language programs in terms of execution speed.
Early Features of Fortran
Assignments, DO loops, , three-way arithmetic IF statements, GOTO statements;
integers, reals, arrays (and very basic string handling)
Fortran Source Code Format
Fortran source code has strict source code format.
*Early programs were entered on a keypunch keyboard onto 80 column punched cards. Each card records one line of code.
TPK Algorithm
designed by Trabb Pardo
and Knuth in 1970s purely for illustration
purpose:
– reads 11 numbers (from the keyboard), storing them
in an array;
– processes the array in reverse order, applying a
mathematical function to each value, and for each
resulted value:
– reports the value or a message saying the value is
too large.
Characteristics of Fortran
Reflecting punched card input practice, Fortran programs were
originally written in a fixed column format.
COBOL
Created at the
end of the 1950s by a committee of the US Dept of Defense.
designed for business data processing rather than for
scientific computing
