Converting Array Type in C#

Question

Lets say I have an method that returns an Array of strings. I want to convert the array of strings to array of integers. How would I do that in C#?

string[] values = {"1","2","3"};

int[] intValues;

 

I want to cast "values" to "intValues". What would be the syntax?

 

Thanks,

Rajesh

Answer 1

Try something like this

 

string[] array = {"1", "2", "3"};

int[] values = new int[array.Length];

for(int x = 0; x < array.Length; x++)

{

   values[x] = Convert.ToInt32(array[x].ToString());

}

 

Nathan

Answer 2

Code Snippet

string[] values = {"1","2","3"};

int[] intValues = new int[values.Length];

for (int i=0;i < values.Length;i++)

{

intValues[i] = Convert.ToInt32(values[i]);

}

 

Nathan beat me to it. :-)

Answer 3

You can't cast, if that's what you're looking for.  You'll have to convert each element, one by one.  For example:

Code Snippet

string[] strings = {"1", "2", "3"};

int[] numbers = new int[strings.Length];

int i = 0;

foreach(String text in strings)

{
  int.TryParse(text, out numbers[i]);
  ++i;

}

foreach(int number in numbers)

{

 Console.WriteLine(number);

}

 

 

Answer 4

Code Snippet

int[] numbers = Array.ConvertAll<string, int>(strings, delegate(string str) { return int.Parse(str); } );

But as already mentionned, this wel generate an exception if there is a string that can't be parsed... So TryParse might be a better option if you want to keep the values that where actually valid...

Answer 5

And the Linq way (available in Orcas)

 

            string[] strings = new[] { "1", "2", "3", "4" };

            int[] ints = strings.Select(x => int.Parse(x)).ToArray();

Marcelo.

Answer 6

when i put this "think" ...(x=> int.Parse(x))... (sorry for my Engilsh) in the For loop,
 and when I build it in second iteration program stops working and i see warning (or whatever): "Input string was not in a correct format."
Would you explain me what I can do with it, plz

Answer 7

You dont have to put this in a for loop.
x=>int.Parse(x).ToArray will convert all the elements of string array to int......

Hope this helps........:)

Answer 8

thx, that helped me a lot.

Answer 9

And the Linq way (available in Orcas)

 

            string[] strings = new[] { "1", "2", "3", "4" };

            int[] ints = strings.Select(x => int.Parse(x)).ToArray();

Marcelo.

Hi guys and thank you dear Marcelo Guerra.

Your answer was exactly correct, but I had another question and I wish that you (or another person in Microsoft support group) give me the best solution.

What can I do when type of second array is unkown?!

I wanna convert a typed array to another parametrized typed array. For example, if I had a array of string type, then I'll give a type as a parameter (ex. typeof(int)) and I've to convert my typed array (first) to given type.

Something like below function... I don't know what's the best method to convert given array to a result of that array with given type.

Regards.

from Antonom
Microsoft Certified Technology Specialist (MCTS)
Microsoft Certified Professional (MCP)
Phone: [phone]

public IList ConvertArray(string[] firstArray, Type targetType)

{

          […]

}

Answer 10

You can use Convert.ChangeType.

    static public IList ConvertArray(string[] firstArray, Type targetType)
    {
      Array array = Array.CreateInstance(targetType, firstArray.Length);
      for (int i = 0; i < firstArray.Length; i++)
      {
        array.SetValue(Convert.ChangeType(firstArray[i], targetType), i);
      }
      return array;
    }

 

Answer 11

You can use Convert.ChangeType.

 static public IList ConvertArray(string[] firstArray, Type targetType)

 {

  Array array = Array.CreateInstance(targetType, firstArray.Length);

  for (int i = 0; i < firstArray.Length; i++)

  {

  array.SetValue(Convert.ChangeType(firstArray[i], targetType), i);

  }

  return array;

 }

 

Dear Louis.fr

Hi.

Although, your solution was correct and I agree with you in this way, but I'm not sure about the constructor of array types. I've found the same as this solution and I'm looking for another trusted way. (without using Convert and reflection resources). There're many exceptions for converting customized types with Convert.ChangeType. Also if I have a array with a parameterless constructor, this code will going to be crashed. Anyway, I'd like to be the best. ;)

I should thank you.

"Best wishes"

from Antonom
Microsoft Certified Technology Specialist (MCTS)
Microsoft Certified Professional (MCP)
Phone: [phone]

Answer 12

1) What is "a array with a parameterless constructor"?

2) There is no universal way to convert between types, except to Object. The closer to universal conversion is to string, but the default ToString method returns only the type name.

Answer 13

 

As first:

 

public class FixedArray

        : ArrayList

{

        public FixedArray()

                : base(100)

        { }

 

        public override bool IsFixedSize

        {

                get

                {

                        return true;

                }

        }

}

 

That’s a fixed size array with a parameterless constructor. ;). You cann't pass this class through CreateInstance(typeof(FixedArray), fixedArray.Length).

As second:

“Dear Louis.fr”

I wanna do something like a complex way of serialization and dependency property structure in WPF.

I’ve to convert every property value to string and convert it back,,,

Got it?

Thank you.

---

Antonom

Answer 14

1) This is not an array. Hence my question about "array constructors".

2) Isn't there already ways to serialize objects?

3) You shouldn't propose your own replies as answer. Specially when it's not answering the OP.

Answer 15

1) This is not an array. Hence my question about "array constructors".

2) Isn't there already ways to serialize objects?

3) You shouldn't propose your own replies as answer. Specially when it's not answering the OP.

Deal Louis.fr:

a. It's a customized array type. what I mean of array is array definition, it's not just brackets!

b. Maybe yes, but in performance issues and output I've many big problems in xml serialization.

c. I'm so sorry. I'm new in here and if You have any instruction of using this CP, I'll hope to give it to me.

'Thank you.'

---

Antonom

Answer 16

An array is a class inheriting from the Array class. No more, no less.

An ArrayList is not an array: it's a list using an array as internal storage. That's why the "Array" part of the name comes first.

Answer 17

Ping Moderator:

could you split this post into two? Once containing the original (and answered) question, and a second one where Antonom invaded?

Many thanks

RK

---

"The improbable we do, the impossible just takes a little longer." (Steven Parker)

Answer 18

var values = {"1","2","3"};
var ints = values.Select(int.Parse).ToArray();

Answer 19

string[] splitter = new string[] { "," };
string []reps = pv.VISIT_TEST.Split(splitter, StringSplitOptions.RemoveEmptyEntries);
Array.Sort(reps);

       List<int> general = new List<int>();
       List<int> specific = new List<int>();

                foreach (string s in reps)
                {
                    int i;
                    if (int.TryParse(s.Trim(), out i))
                    {
                        if (i != 3 && i != 5 && i != 6 && i != 7 && i != 8)
                        {
                            general.Add(i);
                        }
                        else
                        {
                            specific.Add(i);
                        }
                    }
                }
try this one..........

Answer 20

Thanks Marcelo this worked out for me.

Vishwa