Check empty element array of double c#

Question

I'm looking for a code to check if an element of my array of double is empty. I tried with isNaN, string.isNullOrEmpty and 0.0D but nothing to do, I still have this text : Not a Number.

So, do you know any code in C# which is able to check if an element in a an array of double is empty?

Here is my code:

if (!Double.IsNaN(d1.getChiffreAffaireBase()[keyIndex1]))
{
    textBox43.Text = calcMargeCa(d1.getChiffreAffaireBase()[keyIndex1], d1.getChiffreAffairePlus()[keyIndex1]).ToString("0.00");
    textBox44.Text = calcMargeCa(d1.getChiffreAffaireBase()[keyIndex1+1], d1.getChiffreAffairePlus()[keyIndex1+1]).ToString("0.00");
}
else
{
    label13.Hide();
    textBox43.Hide();
    textBox44.Hide();
}

What do you mean by *empty*? `double` is a ValueType, it cannot be "empty". — Frédéric Hamidi, May 30 '16 at 14:26
Post your code then we'll have a better idea of what you're trying to do. — Nasreddine, May 30 '16 at 14:26
I have double[] array = new double[12] and I want to check if array[6]for example has no values. — Vincent Normand, May 30 '16 at 14:27
@VincentNormand edit your code into the question, not in a comment. also add the code you are using to check the array element. — user1666620, May 30 '16 at 14:27
It will always have a value because as @FrédéricHamidi said, value types always have values. — Nasreddine, May 30 '16 at 14:28
@AbdellahOUMGHAR this is always `true` as `double` is a value type that can never be `null`. — René Vogt, May 30 '16 at 14:29
If you have `double[] array = new double[12]`, the array will have 12 values. They can be NaN, or 0.0 (or any other `double` value), but there is no such thing as "empty". — Dennis_E, May 30 '16 at 14:30

Shreevardhan · Answer 1 · 2016-05-30T14:36:39.583

5

if you declare an array like this

double[] array = new double[12];    // elements cannot be null

all elements will be set to 0.

Declare it as nullable, if you really want

var array = new double?[12];    // elements can be null
var isEmpty = (array[6] == null);

or

var isEmpty = !array[6].HasValue;

edited May 30 '16 at 14:36

answered May 30 '16 at 14:31

Shreevardhan

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score 4 · Answer 2 · edited May 23 '17 at 12:16

Value types cannot not have a value (that is to say, they cannot be null) but you could use a Nullable<double> (or double? for short) which can be set to null if you want to indicate that it doesn't have a value. Here's an example:

double?[] array = new double?[12];

then for checking if it has a value you compare it to null:

if (array[6] == null){
    // do your thing
}

Edit:

Off topic but now that you've posted your code I see that you're using double to represent money (Chiffre d'Affaire or Revenue) while that could work, you should use decimal instead

score 1 · Answer 3 · edited May 23 '17 at 12:01

1

Double.IsNaN doesn't check for null values , check this for more or read the documentations about it https://stackoverflow.com/a/7967190/6001737

instead you can use double?[] array = new double?[12]; which is Nullable and you can then check if a certain array value equals null

edited May 23 '17 at 12:01

Community

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answered May 30 '16 at 14:41

Kareem Alaa El-din

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Check empty element array of double c#

3 Answers3