C# Typecast Basic querry

Question

Hi I am new to C# I have a struct like

struct Package
{
Public int[] intvalues;
Public char[] charvalues;
Public string strvalue;
}

Now I have a string

string strquery;

I want to take the value of intvalues of the Package whose name is strquery.

As far as I tried, this didnt work

(Package)strquery.strvalue

Please help

Answer 1

You cant cast a string type to a package type. To get the value of the strvalue you need to create a Package struct object first.

Package package = new Package();
...
string value = package.strvalue;

Answer 2

Well, you can't do anything like that. Because for a string isn't defined any explicit casting operator such as your struct Package.

Also, the strquery.strvalue is completely wrong, as the string doesn't have such a field.

You can try what Phaedrus said.

From what you've said until now I think you are doing something like this:

List<Package> listOfPackages =new List<Package>();
// You fill up here the list
foreach (Package pkg in listOfPackages)
{
   if (pkg.strvalue == strquery)
   {
       Console.WriteLine("found a package with items:");
       // write the pkg.intvalues
       for(int i=0;i<pkg.intvalues.Length;i++)
           Console.Write(pkg.intvalues[i].ToString());
       Console.WriteLine(" ");
    }
}

Answer 3

First, please clarify your code since it doesn't make any sense.

Second, ask yourself why are you using a struct? are you certain you need a struct? and not a class? look at other questions on StackOverflow that get into that topic.

Third

(Package)strquery.strvalue

Is not valid code. strquery is a string and cannot be casted into Package struct. These are not objects related to each other at any level. (except that they both derive from object class)

Fourth if I were to assume you have a collection of Package based on your "question"

I want to take the value of intvalues of the Package whose name is strquery.

You want something like this

int[] foundValues;
foreach(Package pack in packageCollection)
{
   if( pack.strvalue == strquery)
      {
         foundValues = pack.intvalues;
         break;
      }
}

Answer 4

If I understand the question it appears you are need a dictionary of sorts where and int value would be associated with a key. If you changed your struct to look like this:

class Package // I would recommend using a class
{
    Public Dictionary<string, int> intValues;
}

then you could "query" the int value that had the correct key like this...

var strQuery = "intA";
var pakage = new Package()
pakage.intValues = new Dictionary<string, int>()
{
   new KeyValuePair<string, int>("intA", 0),
   new KeyValuePair<string, int>("intB", 0),
   new KeyValuePiar<string, int>("intC", 9),
}

var result = pakage.inValues[strQuery];

But this really is just enumerating a collection to find a value based on a key and your question could really use some clarification. Why don't you post what your trying to do without trying to suggest what code to use...

Answer 5

It appears as though you might be trying to parse a String using your Package struct. If so then you might try something like this by converting your structure to encapsulate and manipulate a string.

struct Package {
    public Package(string str) { //constructor
        strvalue = str;
    }
    public int[] Get_intvalues() { // method version
        // Convert stvalue into int array and return it.
        return new[] {1,2,3}; //example
    }
    public char[] Get_charvalues() { // method version
        return strvalue.ToCharArray();
    }
    public string strvalue; // string to work upon
}

This would allow you to use your Package struct with a string like so:

string str = "this is a test";
Package pkg = new Package(str);
pkg.Get_charvalues();
pkg.Get_intvalues(); //etc.