Question

I’ve a following method “Test” which accepts a params list:

Public void method Test(params double[] list]
{
 Vols vol= new Vols();
//Fill the object based on the input list and
//pass this vol to other private method for further processing
}

Inside this method, am using a custom business object called Vols defined as follows:

public class Vols
{
    private double _vol09;
    private double _vol05;
    private double _vol01;

    public Vols()
    {
    }


    public double Vol09
    {
        get { return _vol09; }
        set { _vol09 = value; }
    }


    public double Vol01
    {
        get { return _vol01; }
        set { _vol01 = value; }
    }


    public double Vol05
    {
        get { return _vol05; }
        set { _vol05 = value; }
    }
} 

The user of method “test” can pass in values as: test(0.1,0.9);

So, depending on the input passed, I want to set only the corresponding property in the business object “Vols”….ie. in this case , properties Vol01 and Vol09 would be set in the method “test”.
Is there any way to do this so that I can avoid a switch case inside the method?

This would be possible using reflection…but since reflection is expensive, is there any other approach I can make use of?Also, shall I use switch-case statement or reflection here wrt good coding practices?

Thanks.

Answer 1

It would be more readable if you used an object initializer…

var test = new Test() { Vol01 = 0.1, Vol09 = ... }

Your constructor can construct the default business object and your property setters can call the corresponding property on Vols.

It also might make sense to use a fluent interface which is always a good choice when there is complex, variable, constructor setup…

var test = new Test().WithVol01(0.1).AndIntentRevealingName();

or, just inject the business object…

var test = new Test(new Vols(...setup how I want it tested...));

And in C# 4.0, you can use named parameters, all the cool kids are doing it…

var test = new Test(vol01: 0.1, ...);

Reflection is overkill, and I wouldn’t be worrying about performance. I would be worrying if my test cases clearly revealed intent.