CODEWITHSUNDEEP
c#
user1500633
user1500633

Reputation:

Need to Concat strings in C# windows

In a list, I'm having some string values based on certain condition. I need to concatenate the string value with another string "SUM()".

For eg:List contains values A1, A2, A3

The output string should be

Sum(A1) as A1,Sum(A2) as A2,Sum(A3) as A3

My code is as follows:

List<string> strList = new List<string>();
foreach (DataRow dr in dt.Rows)
{
    strList .Add(dr[0].ToString());
}
string NewStrSum  = "";
string NewColSum = "";
NewStrSum = "  SUM(";
NewColSum = NewStrSum + String.Join(") ", strList .Select(n => n.ToString()).ToArray());

But the output is Sum(A1)A2

Upvotes: 1

Views: 105

Answers (6)

user836846
user836846

Reputation: 74

You can use as below,

// This is your code
List<string> strList = new List<string>();
                foreach (DataRow dr in dt.Rows)
                {
                    strList .Add(dr[0].ToString());
                }

// New Code
string newColSum = string.Join(",", strList.Select(s => string.Format("SUM({0}) as {0}", s)));

Upvotes: 0

Ariel Batista
Ariel Batista

Reputation: 144

Try to concat the strings inside the bucle foreach

here an example:

string OutPut  = string.Empty;
        foreach (DataRow dr in dt.Rows)
                {
                    OutPut += "SUM("
                            + dr[0].ToString()
                            + ") as ";
                            + dr[0].ToString()
                            +", "; 
                }

Upvotes: 0

Tony Wu
Tony Wu

Reputation: 1107

string result = string.Empty;

for(int i=0;i<strList.Count;i++)
{
    if(i!=0)
    result+= " , ";
    result+= "Sum("+strList[i]+") as "+strList[i];
}

Upvotes: 0

krivtom
krivtom

Reputation: 24916

Why don't you use something like this:

// Create your list
var list = new List<string>();
list.Add("A1");
list.Add("A2");
list.Add("A3");

// Create list of elements that look like 'Sum(X) as X':
var sumList = list.Select(x=>string.Format("Sum({0}) as {0}", x));

// Create single string
var result = string.Join(", ", sumList);
Console.WriteLine(result);

Upvotes: 1

Soner G&#246;n&#252;l
Soner G&#246;n&#252;l

Reputation: 98868

You can use Enumerable.Select to get every element in your List<string> with specified formatted and use it with string.Join to concatenate them with , as;

var list = new List<string>() {"A1", "A2", "A3"};
var newlist = list.Select(s => string.Format("SUM({0}) as {0}", s));
var result = string.Join(",", newlist);

result will be;

SUM(A1) as A1,SUM(A2) as A2,SUM(A3) as A3

Upvotes: 4

Sagi Levi
Sagi Levi

Reputation: 305

Try this:

var list = new List<string> {"A1", "A2", "A3"};
var str = list.Aggregate(string.Empty, (current, item) => current + string.Format("SUM({0}) AS {0},", item));
str = str.Remove(str.Length - 1);

Upvotes: 0

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