How do I get the sum of integers from an array of objects?

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Hello,

I have the following data collections:

C#

object data = new object[] { 1, true, "b", "a", false, 1, null };

I would like to get: 2 since 1 + 1 = 2. I was wondering why my code always returns 0;

Any comments and suggestions would be very much appreciated. I am a beginner. Thank you.

What I have tried:

C#

object data = new object[] { 1, true, "b", "a", false, 1, null };
            var objects = new object[] { data };
            int sum = 0;

            for (int i = 0; i < objects.Length; i++)
            {
                foreach (var element in objects)
                {
                    Type tp = element.GetType();

                    if (tp.Equals(typeof(int)))
                    {
                        sum += (int)element;
                    }
                }
            }
            Console.WriteLine(sum);

Posted 31-Jan-22 1:19am

LuckyChloe

Updated 1-Feb-22 7:36am

Sean Ewington

v2

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4 solutions

Solution 3

Richard already gave you the elegant solution. Now here you are the clumsy fix for your original code

C#

var data = new object[] { 1, true, "b", "a", false, 1, null };
var objects = new object[][] { data };
int sum = 0;

for (int i = 0; i < objects.Length; i++)
{
  foreach (var element in objects[i])
  {
    if ( element!= null)
	{
	  Type tp = element.GetType();
	
	  if (tp.Equals(typeof(int)))
	  {
	    sum += (int)element;
	  }
    }
  }
}
Console.WriteLine(sum);

Posted 31-Jan-22 1:49am

CPallini

Comments

LuckyChloe 31-Jan-22 7:56am

I appreciate it. Thank you

CPallini 31-Jan-22 8:02am

You are welcome.

Patrice T 31-Jan-22 14:22pm

+5

CPallini 1-Feb-22 2:06am

Thank you.

Solution 4

Here's another solution for fun...

C#

object[] data = new object[] { 1, true, "b", "a", false, 1, null };
int sum = 0;

foreach (object item in data)
{
    if (item is null) continue;
    
    if (int.TryParse(item.ToString(), out int value))
        sum += value;
}

Console.WriteLine(sum);

Posted 31-Jan-22 2:06am

Graeme_Grant

Solution 2

You can also modify you code like:

object data = new object[] { 1, true, "b", "a", false, 1, null};
Object[] data2 =  (Object[])data;
int sum = 0;
foreach (var item in data2)
{
        if (item != null)
        {
                Type tp = item.GetType();
                if (tp.Equals(typeof(int)))
                {
                     sum += (int)item;
                }
        }
}
Console.WriteLine(sum);

Posted 31-Jan-22 1:42am

M Imran Ansari

Comments

LuckyChloe 31-Jan-22 7:47am

This is perfect. Thank you very much. I will reflect on what where I made mistakes.

M Imran Ansari 31-Jan-22 8:07am

Great. Happy Coding!!

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Richard Deeming · Accepted Answer · 2022-01-31T01:33:00

Solution 1

There are no int values in your objects array. It contains a single element of type object[].

You're also iterating over the objects array twice - once with the for loop, and once with the foreach loop. You can't currently iterate over the data array, since you've declared the variable as object instead of object[].

Once you've fixed your variable declaration and removed the unnecessary objects array, you can use LINQ to get the sum:

C#

object[] data = new object[] { 1, true, "b", "a", false, 1, null };
int sum = data.OfType<int>().Sum();

Enumerable.OfType<TResult>(IEnumerable) Method (System.Linq) | Microsoft Docs[^]

Posted 31-Jan-22 1:33am

Richard Deeming

Comments

CPallini 31-Jan-22 7:39am

5.

LuckyChloe 31-Jan-22 7:45am

Thank You Very Much Sir. Your Solution 100% solved my problem. I was just wondering since I was taught that LINQ consumes lot of computational resources, would it be possible to accomplish the same thing with foreach loop?

Richard Deeming 31-Jan-22 7:48am

Yes, you can use a foreach loop instead. Solution 2 shows you how - although it would still be better to fix the declaration of the data variable, rather than adding the ugly (object[])data cast.

LuckyChloe 31-Jan-22 7:48am

Another solution provides solution to this problem with foreach loop too so no need to answer my commented question. Thank you very much again