Object-Oriented Development Approach

1. What is the Object-Oriented Approach?

The object-oriented approach (OOA) to software development models problems using objects, which represent real-world concepts.

• An object encapsulates attributes (what the object is) and operations (what the object does).
• Objects interact by sending messages (invoking operations on each other).
• OOA has become the most widespread paradigm over the past 30 years, replacing older methodologies like unstructured and procedural programming.

2. A Bit of History

• First introduced in the 1960s with languages like Simula I and Simula 67 by Dahl and Nygaard.
• Smalltalk (1970s) is often considered the first "pure" object-oriented language, although adoption was initially limited.
• C++ (by Bjarne Stroustrup) in the 1980s and 1990s marked a major breakthrough.
• Popular object-oriented languages: C++, Java, Delphi, C#, and Visual Basic .NET.
• GUIs (graphical user interfaces) especially benefit from OOA.

3. Unstructured Programming

• Early software was one big block of code (the main) with global variables.
• Code was sequential, repetitive, hard to manage, and prone to errors.

4. Procedural Programming