Unformatted text preview: ges to secondgeneration assembly languages brought approximately a seven-to-one
improvement in programmer productivity. A much more significant improvement in programmer productivity was found in the move from second-generation
assembly languages to third-generation high-level languages. The efforts for the
search of new programming languages which could further improve programmer
productivity continued even after the advent of third-generation high-level
languages. The result of these efforts has been the fourth-generation languages,
which claim programmer productivity improvements of 200% to 1000% over
third-generation high-level languages.
There is a major shift in fourth-generation languages as compared to the languages
of previous generations. All previous-generation languages were procedural
languages whereas fourth-generation languages are non procedural languages. A
procedural language (such as COBOL, FORTRAN, BASIC) is one that requires
the programmer to spell out the steps in the processing procedures needed to
achieve a desired result. On the other hand, a non-procedural language allows the
user to simply specify "what" the output should be without describing all the
details of "how" the data should be manipulated to produce that result. With this
type of flexibility provided by fourth-generation languages, many computer users
often find it easier and quicker to write a program themselves than to depend on a
professional programmer who will write a program for generating the desired
report. Fourth-generation languages are so user-friendly that with a day or two of
training and practice, a computer-competent user can learn to write programs,
make inquires, and generate the desired reports on his/her own.
Fourth-generation languages use high-level English-like instructions. They require
the programmer to specify only "what" to do, not "how" to do it. Most of the
procedure portion (steps to carry out the intended task) of a fourth-generation
language program is generated autom...
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This document was uploaded on 04/07/2014.
- Spring '14