C# Reading each value of a returned array.

Question

Hi All,

I have an array being returned but as I'm new to programming I can't work out how to read each value. Can someone please point me in the right direction?

My code is below.

private void testToolStripMenuItem_Click(object sender, EventArgs e)
{
 foreach (int name in getNames()) //<----I'm wrong here I guess
 {
    MessageBox.Show(name.ToString());
 }
}

private ArrayList getNames()
{
 //some code...
 ..
 ...
 return names;
}

Thanks all

Answer 1

Rather than using ArrayList, try using List<int>.

I'm guessing that in the foreach statement, you're hitting a cast exception. It's hard to tell this because you've left out the body of getNames().

Answer 2

Firstly, you're not returning an array, but rather an ArrayList instance. Secondly, why would a name be an int? Surely you mean string? Finally, if you're on .NET 2.0 or later, you can use generics to improve your code. So, use List<string> rather than ArrayList.

private void testToolStripMenuItem_Click(object sender, EventArgs e)
{
    foreach (string name in getNames())
    {
        MessageBox.Show(name);
    }
}

private List<string> GetNames()
{
    var names = new List<string>();
    names.Add("Kent");
    return names;
}

HTH, Kent

Answer 3

The issue here is that getNames returns an arraylist of objects--not ints.

You could rewrite your code with this change:

 foreach (object nameobj in getNames())
 {
    string name = (string)nameobj;
    MessageBox.Show(name);
 }

Alternatively, you could (and should) use generics to keep everything nice and tidy. That might look like this (untested) code:

private void testToolStripMenuItem_Click(object sender, EventArgs e)
{
 foreach (string name in getNames()) 
 {
    MessageBox.Show(name);
 }
}

private IList<string> getNames()
{
 //some code...
 List<string> names = new List<string>();
 names.Add("Scott");
 ..
 ...
 return names;
}

Add a using for System.Collections.Generic. Also, as others noticed, I changed it to string from int.

Answer 4

Hi Scott! Try return a list of int instead. Like this:

private List<int> getNames()
{
    //some code...
     ..
     ...
     return names;
}

Either that, or check that it's really int's in your list, so you've not done anything like list.add("5"). Then the 5 would be a string, not an int.

Answer 5

This may get you started:

String key, val;

foreach (DictionaryEntry de in myArrayList)
{
     key = (String)de.Key;
     val = (MyObjectType)de.Value;
}

EDIT: Updated to remove the IEnumerator version to a foreach version.

Answer 6

ArrayList stores items as objects. So you need to unbox it to the required type (int in your case). But why int and not string for name?