Oct 11 2011

Keep Code Statements Simple

I don’t count my progress by the line of codes but at the same time I don’t take pride by over engineering a solution. Writing code is like writing for a publication, you have to know at what reading level you are writing for. That said, the one type of code statement that gets under my skin is what I call the run-on code statement. A Run-on code statement is one that has multiple method calls in one statement. Here is a made up example of a run-on code statement.


In the above run-on code statement there are four method calls. I’ve seen worse. The reason whey run-on code statements are a pet peeve or mine is that if anyone method call fails because of a NullPointerException or some other error it’s difficult to quickly know what segment of the code statement failed. This is also annoying to debug if you want to step into one method out of the four.

Apr 25 2011

Java String Conversion Puzzlers

In Java, object coercion from one type to another can led to interesting results, and possible bugs when done implicitly. For example, a common type conversion bug is when you have a method that accepts a primitive boolean but pass it an an object of type Boolean. If the object is null, the conversion from a Boolean object to a boolean primitive will cause a NullPointerException.

But mixing between Strings, characters, and integers can result in an interesting mix of results. For example, I think that any Java developer would have some doubt in describing the output from the following Java code.

System.out.println("Hello, "+(char)('A'+1));
System.out.println("Hello, "+('A'+1));
System.out.println("Hello, "+'A'+1);

The one rule to remember about coercion is that if you are performing a calculation with two different types, the least accurate type will be coerced or converted to the more accurate. In this case, adding a character and an integer will result in converting the character to the corresponding integer value before performing the addition operation. Because the integer equivalent of the char value ‘A’ is 65, then ‘A’+1 = 66. When adding between a string, character, and integer the character and integer are converted to strings because concatenating the values into a new string.

"Hello, "+(char)('A'+1); // Hello, B
"Hello, "+('A'+1); // Hello, 66
"Hello, "+'A'+1; // Hello, A1