Setting fields with correct default value

Question

When writing constructors, I regularly encounter a situation where some fields already have approperiate (default) values, such as false for boolean values and 0 for integers. What are reasons to emphasize these values, for example like:

state = 0;

Do you appreciate it when reading someones code? On one side I feel like expressing implementation details explicitly, on the other side I find it pointless to set a field when I'm sure it is already correct.

• Joey: Myself, I tend to do this in C++, but not in C#. Never really thought about why, though.
• svick: Maybe it's because in C++, many types (like int) have undefined default value? This is not a problem in C#.

Answer 1

I work in a projects company. I LOVE it when default values our explicitly defined in the code. This also implies: 1. Definition of the data - is the data type used correct ? 2. The semantic definition of a value - Like in your example, 0 is a clue for an initial state. In some cases I get no clue what 0 means.

Note : State MUST be defined somewhere, be it a CONST value, or an enumeration somewhere. The value 0 has no other meaning than initial state. A string literal might add some more value to it.

• Leopold Asperger: I understand the note, its just an example though. I guess a buffer where the initial position is 0 is more realistic.

Answer 2

Just because you're sure it is correct, that intern over in the other building has no idea. Giving objects a nice sane default is good. Being explicit is good.

And remember, code is there for humans, not computers.

• mattnz: +1 : Also I don't have to wonder what you were thinking if you are explicit. I might be an expert programmer (yeh...I know.... some of my peers will debate that), I am not a mind reader. More importantly, I only have interest in succeeding at one of those skills
• Leopold Asperger: Intern or not, any developer must understand default values.
• Telastyn: @LeopoldAsperger - I heartily disagree. I'm pretty sure I couldn't tell you the default values for all of the different variable declarations for all of the different languages I use today, let alone know. It's trivia, because they shouldn't be counted on.