Revision up to higher abstraction 4th GL

Recap of Third Generation Languages (3GL):

• 2. Modular and Structured Programming:

  • Programs written in modules (subroutines).

  • Subroutines are independent and modifiable.

  • Nesting subroutines – one written within another.

  • Structured programming: Blocks of code with independent details.

  • Procedural languages classified as business, scientific, or multipurpose.

Recap of Fourth Generation Languages (4GL):

• Fourth Generation Languages (4GL):

  • More human-like and programmer-friendly.

  • Features a graphical user interface (GUI).

  • Non-procedural – specifies what to do, not how to do it.

  • Primarily used for retrieving and formatting data.

  • Includes database management languages, report writers, and application generators.

Recap of Fourth Generation Languages (4GL):

• Markup Languages:

  • Declarative languages focusing on data presentation.

  • Do not run routines or perform logical operations.

  • Used to explain how texts should be edited.

  • HTML (HyperText Markup Language) is a common markup language for web pages.

Recap of OOP

Belong to the fourth generation with higher abstraction.

• Used in Object-Oriented Programming (OOP) where programs are built around objects.

• Objects are instructions simulating real-world objects (e.g., a car).

• Objects belong to classes with procedures and data definitions.

• OOP features encapsulation (keeping data together) and abstraction (identifying common patterns).

Recap of Visual Languages

• Also part of the fourth generation with higher abstraction.

• Visual Programming Languages (VPL) use graphical interfaces for program creation.

• Interact with windows, icons, and menus for executing commands (e.g., copy, delete).

• No need to write programs using syntax; uses Integrated Development Environment (IDE).

• VPLs can be hybrid, combining visual and text-based elements.