Bad developer ≠ novice developer

My post on the nature of programming seems to have struck a nerve. Many commenters pondered what makes a developer great. “Ka” thought that:

“You [are] not born [a] good or great programmer, you become one with time and study and hard work. At the beginning, everybody is a bad programmer.”

I disagree. Developers are not born “great,” but greatness does not automatically come with experience. Conversely, lack of experience does not make a developer “bad.” The difference between a great developer and a bad developer is not in their domain knowledge, but their methodology. The distinguishing mark of a great developer is that he codes consciously. Put another way, a good developer always knows why he is doing something. From the perspective of personal ethics, this requires intellectual courage and integrity.

Let me give an illustration of what I mean from personal experience:

When I got into Objective-C development, I was a “bad” developer. Most of my experience is with .Net code. Jumping into the iPhone dev world was intimidating. As as a result, I lacked the courage to learn the architecture. I tried to manipulate blocks of code found on the web without understanding what they were doing. I would copy and paste blocks of code and just change variable names. When things didn’t work, I would look for another block of code to substitute for the failing one, or enter “debugging hell” – running code over and over, making random changes and seeing if they worked. This is the hallmark of a bad developer – imitating without understanding. I kept this up for over a year. It’s not that I didn’t try to learn the language. I got several books and watched iTunes U classes. But the way I used the learning materials was to memorize blocks of code and look for places to stuff them into my code. I wasn’t actually learning the platform, just collecting samples. Some developers spend their entire careers this way. They carry collections of old code everywhere they go, and just grab chunks to insert into new programs. They may never select File => New File or File => New Project in their whole career.

After writing a lot of bad, buggy code, I drifted back to the comfort of .Net. Recently however, I decided to change my attitude. I started by downloading some iPhone code samples and open-source applications. I started in main.m and went through each line of code. If I didn’t understand exactly why a certain symbol was used or what it did, I looked it up. I spent a lot of time on Cocoa Dev, and Stack Overflow looking up things like the reasons why you would assign, retain, or copy a property, or when exactly you need to release an object (for alloc, new, copy or retain) or what you can do with respondsToSelector. There’s really not that much complexity to programming languages – but if you don’t take the time to learn how things work, they will always seem difficult and mysterious. If I had just looked this stuff up to begin with, I would have been far more productive. But, I was intimidated by the environment and tried to shortcut the learning process by imitating without understanding.

Understanding anything complex requires the courage and integrity to engage in difficult, exhausting mental effort. It’s tempting to cheat yourself. It’s easier spend more time in endless copying and debugging that take the effort to understand and create. In the short run, it saves time. But in the long run, developers who understand their craft are magnitudes more productive than the monkey see-monkey do coders. This is the difference between the unprincipled kind of laziness that trades understanding for time and the principled kind of laziness which saves time by understanding.

There’s no happy ending to my story — yet. The proof of a developer is in his work, not his book smarts, and I have yet to produce something to brag about.

For more on the traits of great developers, read these posts by Dave Child and micahel.

Get the MD5 hash of a file in .Net

MSDN has a page on how to get the MD5 hash of a string.

Easy enough, but if you follow their example exactly for a file and use File.ReadAllText() to get the string, you will get the wrong MD5 string for binary files. Instead, use File.ReadAllBytes() to bypass encoding issues. (This also applies to SHA1 hashing.)

private static string GetMD5Hash(string filePath)
            byte[] computedHash = new MD5CryptoServiceProvider().ComputeHash(File.ReadAllBytes(filePath));
            var sBuilder = new StringBuilder();
            foreach (byte b in computedHash)
            return sBuilder.ToString();