Easy initialization of string arrays within a class

Question

If a class contains just string array variables, is there an easy way to initialize them all without having to type the same code over and over?

For example, if I have something like

[Serializable]
public class ReadDiagnosticEntirePointValuesResponse
{
    public string[] pointidentifier;
    public string[] presentvalue;
    public string[] priorityarray;
    public string[] alarmstate;
    public string[] outofservice;
    public string[] correctvalue;
    public string[] affect;
    public string[] covenable;
    public string[] covincrement;
    public string[] covtarget;
    public string[] covlifetime;
    public string[] historyenable;
    public string[] historyincrement;
    public string[] elapsedactivetime;
    public string[] feedbackvalue;
    public string[] rawvalue;
    ...//A lot more 
}

and I want to assign values to to them, I want to avoid doing:

        ReadDiagnosticEntirePointValuesResponse response = new ReadDiagnosticEntirePointValuesResponse();


        response.affect = new string[count];
        response.alarmstate = new string[count];
        response.correctvalue = new string[count];
        response.covenable = new string[count];
        response.covincrement = new string[count];
        response.covlifetime = new string[count];
        response.covtarget = new string[count];
        response.elapsedactivetime = new string[count];
        response.feedbackvalue = new string[count];
        response.historyenable = new string[count];
        response.historyincrement = new string[count];
        response.outofservice = new string[count];
        response.pointidentifier = new string[count];
        response.presentvalue = new string[count];
        response.priorityarray = new string[count];
        response.rawvalue = new string[count];
        ...

Sure, I could write those initialization in constructor but that still doesn't save me from having to manually initialize them all.

What's a good way to avoid this?

I’d suggest you rethink your design. In this case, it rather looks like you need only one array of structured data. — Konrad Rudolph
– Konrad Rudolph, Commented Sep 13, 2012 at 6:48
Why can't you use List<string> or List<CustomClass>, Where CustomClass has all your data — Raghuveer
– Raghuveer, Commented Sep 13, 2012 at 6:49
Agree with @Konrad; a YourTypeHere[] where YourTypeHere defines a PointIdentifier, PresentValue, AlarmState, etc would be far preferable. Also; I doubt they all need to be strings! — Marc Gravell
– Marc Gravell, Commented Sep 13, 2012 at 6:49
That is the interface I am given which follows a protocol known as SOAP. I can't deviate from it but if intermediate steps involve using list (or any other class) to meet what I need, then that is fine too. — TtT23
– TtT23, Commented Sep 13, 2012 at 6:50
that layout isn't mandated by SOAP; it is simply how you have chosen to lay out the data inside the SOAP envelope. Indeed, you can't change this arbitrarily (client(s) and server(s) must agree on the layout), but: on a green-field system, there is nothing in SOAP that makes you use that layout. — Marc Gravell
– Marc Gravell, Commented Sep 13, 2012 at 6:57

Marc Gravell · Accepted Answer · 2012-09-13 06:50:34Z

That is a pretty horrible way to manage your data, however, something like the following would work....

foreach(var field in GetType().GetFields()) {
    if(!field.IsStatic) field.SetValue(this, new string[count]);
}

However! I strongly suggest you rethink this design. A better mechanism would be:

class DiagnosticPoint // TODO: rename as appropriate
{  // TODO: check these all need to be strings
    public string Affect {get;set;}
    public string AlarmState {get;set;}
    ...
    public string RawValue {get;set;}
}

and have an array of that as a field:

public class ReadDiagnosticEntirePointValuesResponse
{
    DiagnosticPoint[] points;
    ...

then simply init the array:

points = new DiagnosticPoint[count];

and init each:

for(int i = 0 ; i < count ; i++) points[i] = new DiagnosticPoint();

and access via:

var alarm = points[index].AlarmState;

(etc)

cuongle · Accepted Answer · 2012-09-13 07:03:53Z

1

You can use Reflection to do this:

public ReadDiagnosticEntirePointValuesResponse()
{
    GetType().GetFields(BindingFlags.Instance | BindingFlags.Public)
             .ToList()
             .ForEach(field => field.SetValue(this, new string[count]));
}

edited Sep 13, 2012 at 7:03

answered Sep 13, 2012 at 6:50

cuongle

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Comments

Azodious · Accepted Answer · 2012-09-13 06:49:34Z

0

At least once you have to initialize them manually. if C'tor doesn't suit you, initialize in a new method.

answered Sep 13, 2012 at 6:49

Azodious

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woodbase · Accepted Answer · 2012-09-13 06:49:34Z

0

You might want to look at reflection for that... Reading the class' proprties in a loop

answered Sep 13, 2012 at 6:49

woodbase

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Comments

Enigmativity · Accepted Answer · 2012-09-13 07:09:40Z

This sounds like an awful class definition. Perhaps using an enum might be better.

If you could start with this:

public enum ReadDiagnostic
{
    pointidentifier,
    presentvalue,
    priorityarray,
    alarmstate,
    outofservice,
    correctvalue,
    affect,
    covenable,
    covincrement,
    covtarget,
    covlifetime,
    historyenable,
    historyincrement,
    elapsedactivetime,
    feedbackvalue,
    rawvalue,
}

You could then create a Dictionary<ReadDiagnostic, string[]> to hold your values that you were storing in your class.

You could even use LINQ to create your dictionary in one line of code:

var readDiagnosticEntirePointValues =
    typeof(ReadDiagnostic)
    .GetEnumValues()
    .Cast<ReadDiagnostic>()
    .ToDictionary(x => x, x => new string[count]);

This approach is still strongly-typed, but much easier to maintain than your current approach.

Rudey · Accepted Answer · 2012-09-13 07:23:56Z

You could use the following:

response.affect = response.alarmstate = response... = new string[count];

However, using this will still have you initialize them manually. It's just a shortcut.

As others may already have suggested, using Collection Classes will make it a lot easier. I would recommend a Dictionary. Here is how you could implement it:

enum Foo { Affect, AlarmState, CorrectValue, ... }

public void InitializeArrays(int count)
{
    Dictionary<Foo, string[]> response = new Dictionary<Foo, string[]>();

    // easy initialization of string arrays
    foreach (Foo foo in Enum.GetValues(typeof(Foo)))
    {
        response.Add(foo, new string[count]);
    }

    // use this to access the string arrays
    response[Foo.Affect][0] = "test";

    if (response[Foo.CorrectValue].Length > 0) { ... }
}

Alternatively, you could also achieve the same by using a Multidimensional Array.

// initialize it like this
string[,] response = new string[Enum.GetValues(typeof(Foo)).Length, count];

// access it like this
response[(int)Foo.Affect, 0] = "test";

Uwe Keim · Accepted Answer · 2012-10-06 14:08:37Z

0

You can use the array list to avoid of declaring the size.

edited Oct 6, 2012 at 14:08

Uwe Keim

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answered Sep 13, 2012 at 6:48

Ranjit Kumar

1

1 Comment

carlpett Over a year ago

But there might be a good reason for having fixed-length arrays. Possibly there needs to be exactly count elements, no more, no less.

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