How do I build a generic C# array content printer that accepts both objects and primitives?

Question

I'm just trying to quickly debug a webservice by printing out the contents of an int and string array. Is there anyway to do this in one method?

I tried

public static string ArrayToString(object[] array)
{
    StringBuilder sb = new StringBuilder();

    foreach (Object item in array)
    {
        sb.Append(item.ToString());
        sb.Append(" ");
    }

    return sb.ToString();
}

But this chokes when I try and send it a primative array (int[]) due to it not being an Object.

Which I find strange as sending an int to the method below works

static void PrintObject(object obj)
{
    Console.WriteLine(obj.ToString());
}

Is there anyway to do this in one method or am I just going to have to man up and create two separate methods?

---

Of course whether I should be using arrays at all is questionable, but the web service is already in place.

See also:

• When to use a Array() over Generic.Lists in .NET
• Arrays considered somewhat harmful

Answer 1

public static string ArrayToString<T>(T[] array)
{
   StringBuilder sb = new StringBuilder();

    foreach (T item in array)
    {
        sb.Append(item.ToString());
        sb.Append(" ");
    }

    return sb.ToString();
}

Then

int[] x = new int[] { 1, 2, 3 };

string[] y = new string[] { "a", "b", "c" };

Console.WriteLine(ArrayToString(x));
Console.WriteLine(ArrayToString(y));

Answer 2

Try something like this:

static String toString<T>(IEnumerable<T> list)
{
    StringBuilder sb = new StringBuilder();

    foreach (T item in list)
    {
        sb.Append(item.ToString());
        sb.Append(" ");
    }

    return sb.ToString();
}

The compiler will happily infer the type of T by the type of the list you pass in like this:

toString(new int[] { 1, 2, 3 });
toString(new String[] { "1", "2", "3" });

Answer 3

Why did you choose an array? Your code depends on none of the specific properties of an array and instead just sees a list of objects. It seems like IEnumerable would be a much better choice and would allow for virtually any collection of objects

public static string ArrayToString(IEnumerable source)
{
    StringBuilder sb = new StringBuilder();

    foreach (Object item in source)
    {
        sb.Append(item.ToString());
        sb.Append(" ");
    }

    return sb.ToString();
}

Answer 4

private string PrintObjects<T>(IEnumerable<T> objs)
{
    return string.Join(" ", objs.Select(o => o.ToString()).ToArray());
}

Answer 5

There are a few ways to do this.

If you have Linq, you could do

int[] foo = new int[] {1,2,3,4};
ArrayToString(foo.Cast<Object>().ToArray());

and then send it.

Or, you could make a generic extension method

public static string ToString<T>(this IEnumerable<T> val)
{
    StringBuilder sb = new StringBuilder();
    foreach(var item in val) 
    {
       sb.Append(item.ToString());
       sb.Append(" ");
    }
    return sb.ToString();
}