NIOS Computer Science Chapter 3 – Computer Software Part 3

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Difference between 3 GLs and 4 GLs :

Table show Difference between 3 GLs and 4 GLs

Third-generation Languages

Fourth-generation Language

Intended for use by professional Programmers.

A non-programming programmers. Personnel as well as a professional programmer.

Requires specification of how to perform task.

Requires specification of what task is to be performed.

All alternatives must be specified.

Default alternatives are built in; an end user need not specify these alternatives

Require large number of procedural instructions.

Require fewer instructions.

Can be difficult to learn.

Easy to learn.

Difficult to debug.

Easy to debug.

Typically file-oriented.

Typically database-oriented.

Natural Languages:

Natural languages are still in the developmental stages, but they promise to have profound effect, particularly in the areas of artificial intelligence and export systems.

Natural languages have two characteristics:

  1. They are designed to make the connections that humans have with computers more natural - more humanlike.

  2. They are designed to allow the computer to become "smarter" - to actually simulate the learning process by remembering and improving upon earlier information.

Two popular natural languages are LISP and PROLOG.

Compilers and Interpreters:

A high-level language to work on the computer it must be translated into machine language.

There are two kinds of translators:

1. Compilers

2. Interpreters

A compiled language: Compiled language a translation program is run to convert the high-level language program. Called the source code, into a machine language code.

An interpreted language: An interpreted language translation program converts each program statement into machine code just before the program statement is to be executed.

  • Translation and execution occur immediately, one after another, one statement at a time.

  • Unlike the compiled language, no object code is stored and there is no compilation.

  • The most frequently used interpreted language is BASIC.

  • Compiled languages are better than interpreted languages as they can be executed faster and more efficiently once the object code has been obtained.