Author Archives: Hayim Makabee

Unknown's avatar

About Hayim Makabee

Veteran software developer, enthusiastic programmer, author of a book on Object-Oriented Programming, co-founder and CEO at KashKlik, an innovative Influencer Marketing platform.

The Liskov Substitution Principle and Test-Driven Development

Posted on October 5, 2010 by Hayim Makabee

The Substitution Principle, first defined by Barbara Liskov, says that: “Let q(x) be a property provable about objects x of type T. Then q(y) should be true for objects y of type S where S is a subtype of T.” … Continue reading →

Posted in OOD, OOP, TDD | Tagged , , | 3 Comments

When a square is not a rectangle

Posted on September 20, 2010 by Hayim Makabee

In my previous post, I’ve used the example of squares and rectangles to illustrate the importance of definitions. It is clear that, from a geometric point-of-view, a square is indeed a kind of rectangle. However, as my friend Arnon has … Continue reading →

Posted in OOD, OOP | Tagged , | 4 Comments

Is a square a rectangle? – On the importance of definitions

Posted on September 15, 2010 by Hayim Makabee

Before you continue reading this post, please answer the following question:  “Is a square a rectangle?” This is apparently a very simple question, to which we should be able to answer almost immediately, without even thinking about it. However, if … Continue reading →

Posted in OOD, Requirements Specification | Tagged , | 2 Comments

Efficiency vs. Effectiveness

Posted on September 12, 2010 by Hayim Makabee

This is a blog about Effective Software Design, so it is important to first make clear what do we mean by “effective”. Peter Drucker defined the difference between being efficient and being effective: • Efficiency is the capacity to do … Continue reading →

Posted in Efficacy | Tagged | 6 Comments