Does Array.ToString() provide a useful output?

Question

If I have an array and perform a ToString() does that just string together the array values in one long comma seperated string or is that not possible on an arr

Answer 1

You can certainly do that, but it's not the default behaviour. The easiest way to do that (from .NET 3.5 anyway) is probably:

string joined = string.Join(",", array.Select(x => x.ToString()).ToArray());

MoreLINQ has a built-in method to do this:

string joined = array.ToDelimitedString();

or specify the delimited explicitly:

string joined = array.ToDelimitedString(",");

Answer 2

Option 1

If you have an array of strings, then you can use String.Join:

string[] values = ...;

string concatenated = string.Join(",", values);

Option 2

If you're dealing with an array of any other type and you're using .NET 3.5 or above, you can use LINQ:

string concatenated = string.Join(",",
                          values.Select(x => x.ToString()).ToArray());

Answer 3

It doesn't (as you noticed).

For string arrays you can use:

string.Join(",", myArray)

for other arrays I think you need to code it yourself.

Answer 4

No, ToString of an array will give you the Type name string of the object. use String.Join method instead.

Answer 5

To achieve this effect you should call String.Join(string, string[])

I.e.

string[] stringArray = new string[] { "a", "b", "c" };
string.Join(",", stringArray);

Answer 6

You can use string.Concat(Object[] args). This calls the ToString() method of every object in args. In a custom class you can override the ToString() method to achieve custom string conversion like this:

public class YourClass
{
    private int number;

    public YourClass(int num)
    {
        number = num;
    }

    public override string ToString()
    {
        return "#" + number;
    }
}

Now you can concatenate an array of instances of your custom class:

YourClass[] yourArray = { new YourClass(1), new YourClass(2), new YourClass(3) };
string concatenated = string.Concat(yourArray);

Unfortunately this method does not add any delimiters, but I found it to be elegant. The variable concatenated will contain "#1#2#2".