Favor 'Read' Time over 'Write' Time

There are thousands of books and millions of web pages that will define modularity and explain you how to achieve them in your program. I am not going to talk about that here. I will answer you why modularity is important.

Any program can be written in just one single method (or function). At least theoretically? The people who are new to programming do this till they are told about "Abstraction", "Encapsulation", etc. Still I see many programmers not following this. They don't modularize their program well. Sure, they understand what is going on but it's not about them. Code should be written keeping in mind that it will be read many times by many people.

557774423456789.

Can you repeat the number? Don't peak! :-)

(Most of us would have not even read it completely just looking at those many digits)

Now, read this: 55-777-44-23456789.

So, which one was easier to read? And which one was easier to write? The first form (without the hyphen separator) was easier to write if you have this number memorized but it is hard to read and recollect for someone who is not familiar with this number. At the same time, the second form took some more time to carefully break at the right places and make it easy for the reader. We invested some more time in writing to save a lot of time for others to memorize this.

This is the whole point. When you write code, you surely understand and it may seem trivial and waste of time to do "separation of concerns." But it's not about you or me, its about that someone who is going to maintain your code in future long after you have moved to another project. Make sure that she won't curse you :-)