Fourth Generation Language

What is a Fourth Generation Language?

Fourth-generation language is also called 'Language High productivity', 'non-procedural language', 'Creator application'.

Characteristic of fourth-generation languages are:

- No need long training on DP.

- Language to all users (DP professional to the end user)

- Language query

- Constructor application

- Include a procedural language or nonprosedural

Some fourth-generation language to meet the above criteria are not part of.

Language Generation Computers:

First generation language machine language

- There is no interpreter / compiler

- Programmed with the binary notation

- Hard to not make mistakes.

example: 011011 000000 000000 000001 110101

means: clear the contents of the accumulator input 117 to a storage location dlmnya

Second Generation Language assembly language (1950's)

- Addressing a symbolic rather than physical addresses.

- Consists of: SAP, AUTOCODER, SPS, BAL and EASYCODER.

Example: CLA SALARY

Salary indicates a memory location where the variable salary saved.

Third generation language high-level language (1960s)

- Use words English language

- Emphasizing the formula in math notation

- Camp programs converted to run pd yg machines differently.

- Consists of: ALGOL, FORTRAN, COBOL, PL / I and ADA.

Example: x = (a + b) / (c + d)

Fourth Generation Language high productivity language (1970's)

- Accelerate the process of making the application (fewer lines of code)

- Simplify and accelerate the application changes.

- Minimize the debugging problem.

- Users can solve their own problems.

- Consists of: Informix, Oracle

Language of Fifth Generation Artificial Intelligence '(1980s)
- Knowledge-based systems

- Machine can describe the conclusions based on knowledge of complex code.
- Consists of: Prolog, LISP

Language Procedural and Non-Procedural

* Language Procedural determine 'How' things done.

* Language Nonprosedural decide 'Is' to be resolved.

# Language Procedural:

- Programmer provides detailed instructions on how each task completed.

- Example: COBOL, PL / I

# Language Nonprosedural:

- Users get results fast, without saying how that procedure done.

- Almost all language queries, preparing reports, graphs and creator package is nonprosedural application.

- Example: Informix, Nomad

Characteristics, Properties and Components

Main criteria in 4GL:

- Whether intended for routine calculations or making ad-hoc decision?

- Whether destined for the end user or the DP professional?

- Whether the need of a skilled programmer or analyst who used it?

- Which features are provided? (exp. simple queries, preparing reports)

- Whether on-line or off-line?

- Whether running for mainframe, mini or pc?

- Is quite easy to use and fast results obtained?

4GL Property:

In order for a language called 'Fourth Generation' must have the following characteristics:

1. User-friendly.

2. Non-professional programmer can get the results

3. Using DBMS directly.

4. Programs for all applications can be made with a single command fewer instructions.

5. Arranged for operation on-line.

6. Facilitate the understanding and treatment of other people code.

7. Prototype can be created and modified quickly.


· 4GL Components:

In 4GL has pemrogramman non procedural components hidden in munkin procedural facilities. As shown in the following figure.

Appli. Parameters: naming procedures, catalog, version and responsibility.

Spec Data: specification of data and data files used.

Screen spec: determining the form of display.

Report Spec: determining specifications of reports based on data taken.

Dialogue spec: providing the structure and computer interaction.

Specification of Rules: the rules for determining the decision. Usually separated from the body of the application.
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