Question

Which is a better programming practice and why?

I have a class like this:

class data {

    public double time { get; internal set; }
    public double count { get; internal set; }
    public average_count { ... }

}

Where average_count should be read_only and give a calculation of count / time.

Is it better to write the accessor as:

public average_count { get {

    return (time == 0) ? 0 : (count / time);

}}

Or should I do something like:

private _avg_count;

public average_count {
    get 
    {
        return _avg_count;
    }

    internal set
    {
        return _avg_count;
    }
}

Where _avg_count is updated when in the time and count set accessors?

It seems like the first is easier to read but may be slower if average_count is accessed often. Will the compiler optimizations make the difference insignificant?

Answer 1

Doing it on the fly results in more readable code. Precalculating may improve performance, but you should only do this if (a) it’s necessary and (b) you’ve profiled and it makes a difference.

The bottom line is, readability and maintainability should only be sacrificed for performance when it’s absolutely necessary.