Object Oriented Programming Principles and Patterns

What is Programming? Programming is the craft of transforming requirements into something that a computer can execute .

Programming is the craft of transforming requirements into something that a computer can execute .

Evolution… 1940s. First computer users wrote machine code by hand. 1950s. Early tools, such as macro assemblers and interpreters were created and widely used to improve productivity and quality . 1960s. Second generation tools like optimizing compilers and inspections were being used to improve productivity and quality . First large scale (1000 programmer) projects .

1940s. First computer users wrote machine code by hand.

1950s. Early tools, such as macro assemblers and interpreters were created and widely used to improve productivity and quality .

1960s. Second generation tools like optimizing compilers and inspections were being used to improve productivity and quality . First large scale (1000 programmer) projects .

Evolution… 1970s. Collaborative software tools, such as UNIX, code repositories, make , and so on. 1980s. Personal computers became common. Rise of consumer software. Smalltalk: First Object Oriented Programming language/platform that is UI based, Memory Managed, VM Image based, s cripted/incremental .

1970s. Collaborative software tools, such as UNIX, code repositories, make , and so on.

1980s. Personal computers became common. Rise of consumer software. Smalltalk: First Object Oriented Programming language/platform that is UI based, Memory Managed, VM Image based, s cripted/incremental .

Evolution… 1990s. OOP and agile processes (like XP) gained mainstream acceptance. N ew technologies allowed software to grow more complex . 2000s. Managed code and interpreted platforms such as Java, .NET, Ruby, Python, PHP made writing software easier than ever before.

1990s. OOP and agile processes (like XP) gained mainstream acceptance. N ew technologies allowed software to grow more complex .

2000s. Managed code and interpreted platforms such as Java, .NET, Ruby, Python, PHP made writing software easier than ever before.

And where is PL/SQL at?

Procedural Programming Programmer implements requirements by breaking them down to small steps (functional decomposition) Programmer creates a “recipe” that computer can understand and execute

Programmer implements requirements by breaking them down to small steps (functional decomposition)

Programmer creates a “recipe” that computer can understand and execute

Procedural Programming What’s wrong with Procedural Programming? When requirements change It’s hard to implement new features that were not planned in the beginning Code blocks get bigger and bigger Changes in code usually introduce many bugs Code gets hard to maintain

What’s wrong with Procedural Programming?

When requirements change

It’s hard to implement new features that were not planned in the beginning

Code blocks get bigger and bigger

Changes in code usually introduce many bugs

Code gets hard to maintain

Worst thing is that Requirements always change

Requirements

always change

Object Oriented Programming Breaks down requirements into objects with responsibilities , not into functional steps . Embraces change of requirements By minimizing changes in code Lets you think about object hierarchies and interactions instead of program control flow A completely different programming paradigm

Breaks down requirements into objects with responsibilities , not into functional steps .

Embraces change of requirements

By minimizing changes in code

Lets you think about object hierarchies and interactions instead of program control flow

A completely different programming paradigm

OOP is Evolution

OOP Fundamentals

Main Principles

Design Patterns What? Why? When? How?

What?

Why?

When?

How?

Structure of a Pattern

Design Pattern Space

The Bible Hard Version Easy Version

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