How to iterate through two dimensional array

Question

I have two list that I convert them to a single two dimesnional array like this:

double[,] data = new double[voltage.Count(), 2];
for (int i = 0; i < voltage.Count(); i++)
{
    data[i, 0] = voltage[i];
    data[i, 1] = current[i];
}

Now I am trying to itterate through this array but what I get is same value for both voltage and current in each line:

foreach (double data in ztr.GetCurveDataForTestType()) //this will return my array
{
    richTextBox1.AppendText("Voltage" + data + "    ---------    ");
    richTextBox1.AppendText("Current" + data + "\r\n");
}

Voltage-0.175 --------- Current-0.175
Voltage-9.930625E-06 --------- Current-9.930625E-06
Voltage-0.171875 --------- Current-0.171875
Voltage-9.53375E-06 --------- Current-9.53375E-06
Voltage-0.16875 --------- Current-0.16875

As you see in the first line both voltage and current are same value that is voltage, and on the second raw they are the same again but this time it is the current value. How can I fix this?

Answer 1

I'd recommend not using multi-dimensional arrays for this.

Instead you can make a class something like this:

class Measurement
{
    public double Voltage { get; set; }
    public double Current { get; set; }
}

And change your method to return IEnumerable<Measurement> . In .NET 4.0 you can use Zip :

public IEnumerable<Measurement> GetCurveDataForTestType()
{
    return voltage.Zip(current,
        (v, c) => new Measurement { Voltage = v, Current = c});
}

And for older versions of .NET:

public IEnumerable<Measurement> GetCurveDataForTestType()
{
    for (int i = 0; i < voltage.Count(); i++)
    {
        yield return new Measurement
        {
            Voltage = voltage[i],
            Current = current[i]
        };
    }
}

Then your code becomes:

foreach (Measurement data in ztr.GetCurveDataForTestType())
{
    richTextBox1.AppendText(
        "Voltage: {0} ---------  Current: {1}", data.Voltage, data.Current);
}

Answer 2

You use the same kind of loop as when you created the array:

for (int i = 0; i < data.GetLength(0); i++) {
  richTextBox1.AppendText("Voltage" + data[i, 0] + "    ---------    ");
  richTextBox1.AppendText("Current" + data[i, 1] + "\r\n");
}

Answer 3

Update: This question appears to be a duplicate of How to foreach through a 2 dimensional array? . The linked answer has an alternate solution that enables the use of foreach by switching from a two-dimensional array to an array of array.

---

foreach with a two dimensional array, will sequentially return every double value in the array (by design).

For example, given the following two-dimensional array of doubles:

var array = new double[,] { { 0, 1, }, { 2, 3 }, { 4, 5 } };

foreach (var d in array)
{
    Console.WriteLine(d);
}

You will get the following Console output:

0
1
2
3
4
5

Therefore, foreach is not appropriate for you needs . You should use a for loop.