Convert a list into a comma-separated string

Question

My code is as below:

public void ReadListItem()
{
     List<uint> lst = new List<uint>() { 1, 2, 3, 4, 5 };
     string str = string.Empty;
     foreach (var item in lst)
         str = str + item + ",";

     str = str.Remove(str.Length - 1);
     Console.WriteLine(str);
}

Output: 1,2,3,4,5

What is the most simple way to convert the List<uint> into a comma-separated string?

For anyone who wants to reopen this, if it's not too localized it's a duplicate: http://stackoverflow.com/questions/799446/creating-a-comma-separated-list-from-iliststring-or-ienumerablestring — Tim Schmelter, Feb 19 '13 at 14:40
Similar (from 2008): *[How can I join int\[\] to a character-separated string in .NET?](https://stackoverflow.com/questions/145856)* — Peter Mortensen, Jun 11 '21 at 01:29

score 421 · Accepted Answer · edited Jun 02 '19 at 08:51

421

Enjoy!

Console.WriteLine(String.Join(",", new List<uint> { 1, 2, 3, 4, 5 }));

First Parameter: ","
Second Parameter: new List<uint> { 1, 2, 3, 4, 5 })

String.Join will take a list as a the second parameter and join all of the elements using the string passed as the first parameter into one single string.

edited Jun 02 '19 at 08:51

Arun Prasad E S

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answered Feb 19 '13 at 14:27

Richard Dalton

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11

In .NET 3.5 and below you have to explicitly convert your list to array with `lst.ToArray()`, as there is no direct overload there yet. – Anton Dec 15 '13 at 11:09

score 84 · Answer 2 · answered Feb 19 '13 at 14:27

84

You can use String.Join method to combine items:

var str = String.Join(",", lst);

answered Feb 19 '13 at 14:27

Sergey Berezovskiy

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2

this does not work for me. It produces the name of the collection rather than the objects in the list. – Rani Radcliff Oct 21 '19 at 15:15
You need to select the property of a class. e.g. `String.Join(",", lst.Select( x => x.Id ));` – Dhaval Tejlavwala Aug 25 '23 at 07:58

score 33 · Answer 3 · edited Jun 11 '21 at 01:00

33

Using String.Join:

string.Join<string>(",", lst);

Using LINQ aggregation:

lst .Aggregate((a, x) => a + "," + x);

edited Jun 11 '21 at 01:00

Peter Mortensen

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answered Feb 19 '13 at 14:30

Muhammad Hani

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I have list of type int32. when I use aggregate function you mentioned, it says "Cannot convert lambda expression to delegate type 'System.Func' because some of the return types in the block are not implicitly convertible to the delegate return type " and "Cannot implicitly convert type 'string' to 'int'" – Hari Jan 14 '15 at 12:31
1

@Hari You must convert it to string values before you Aggragate to string. So you can do something like this: list.Select(x => string.Format("{0}:{1}", x.Key, x.Value)).Aggregate((a, x) => a+ ", " + x); – bets Jul 20 '17 at 08:14

Rejwanul Reja · Answer 4 · 2018-03-18T08:09:34.407

11

If you have a collection of ints:

List<int> customerIds= new List<int>() { 1,2,3,3,4,5,6,7,8,9 };

You can use string.Join to get a string:

var result = String.Join(",", customerIds);

Enjoy!

edited Mar 18 '18 at 08:09

answered Aug 18 '17 at 09:43

Rejwanul Reja

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This is essentially identical to [the accepted answer from 2013](https://stackoverflow.com/questions/14959824/convert-list-into-comma-separated-string/14959865#14959865). – Peter Mortensen Jun 11 '21 at 01:13

score 10 · Answer 5 · edited Jun 11 '21 at 01:01

10

Follow this:

List<string> name = new List<string>();

name.Add("Latif");
name.Add("Ram");
name.Add("Adam");
string nameOfString = (string.Join(",", name.Select(x => x.ToString()).ToArray()));

edited Jun 11 '21 at 01:01

Peter Mortensen

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answered Apr 11 '15 at 06:59

Salim Latif Waigaonkar

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score 6 · Answer 6 · edited Jun 11 '21 at 01:07

6

You can refer to the below example for getting a comma-separated string array from a list.

Example:

List<string> testList= new List<string>();
testList.Add("Apple"); // Add string 1
testList.Add("Banana"); // 2
testList.Add("Mango"); // 3
testList.Add("Blue Berry"); // 4
testList.Add("Water Melon"); // 5

string JoinDataString = string.Join(",", testList.ToArray());

edited Jun 11 '21 at 01:07

Peter Mortensen

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answered Mar 23 '16 at 16:37

Gaurang Dhandhukiya

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score 5 · Answer 7 · answered Feb 12 '17 at 12:27

5

You can use String.Join for this if you are using .NET framework> 4.0.

var result= String.Join(",", yourList);

answered Feb 12 '17 at 12:27

Abdus Salam Azad

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score 4 · Answer 8 · edited Jun 11 '21 at 01:03

4

@{ var result = string.Join(",", @user.UserRoles.Select(x => x.Role.RoleName));
    @result
}

I used in MVC Razor View to evaluate and print all roles separated by commas.

edited Jun 11 '21 at 01:03

Peter Mortensen

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answered Sep 30 '15 at 10:14

Syed Qasim Abbas

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score 2 · Answer 9 · answered Feb 19 '13 at 14:37

2

Try

Console.WriteLine((string.Join(",", lst.Select(x=>x.ToString()).ToArray())));

HTH

answered Feb 19 '13 at 14:37

Jay

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score 1 · Answer 10 · edited Jun 11 '21 at 01:10

1

We can try like this to separate list entries by a comma:

string stations = 
haul.Routes != null && haul.Routes.Count > 0 ?String.Join(",",haul.Routes.Select(y => 
y.RouteCode).ToList()) : string.Empty;

edited Jun 11 '21 at 01:10

Peter Mortensen

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answered Feb 19 '17 at 09:37

Ajeet Singh

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score 1 · Answer 11 · edited Jun 11 '21 at 01:12

static void Main(string[] args) {
    List<string> listStrings = new List<string>() {"C#", "ASP.NET", "SQL Server", "PHP", "Angular"};
    string CommaSeparateString = GenerateCommaSeparateStringFromList(listStrings);
    Console.Write(CommaSeparateString);
    Console.ReadKey();
}

private static string GenerateCommaSeparateStringFromList(List<string> listStrings){return String.Join(",", listStrings);}

Convert a list of string to a comma-separated string in C#

score 0 · Answer 12 · edited Jun 11 '21 at 01:16

You can also override ToString() if your list items have more than one string:

public class ListItem
{
    public string string1 { get; set; }

    public string string2 { get; set; }

    public string string3 { get; set; }

    public override string ToString()
    {
        return string.Join(
        ","
        , string1
        , string2
        , string3);
    }
}

To get a CSV string:

ListItem item = new ListItem();
item.string1 = "string1";
item.string2 = "string2";
item.string3 = "string3";

List<ListItem> list = new List<ListItem>();
list.Add(item);

string strinCSV = (string.Join("\n", list.Select(x => x.ToString()).ToArray()));

score 0 · Answer 13 · edited Jan 10 '20 at 10:39

0

categories = ['sprots', 'news'];
categoriesList = ", ".join(categories)
print(categoriesList)

This is the output: sprots, news

edited Jan 10 '20 at 10:39

answered Jan 10 '20 at 09:56

sudharsanan r

1

From what C# version is this valid? – Peter Mortensen Jun 11 '21 at 01:17
Is this Javascript? (the question is about C#) – Hans Keﬆing Jun 11 '21 at 12:09

score 0 · Answer 14 · answered Jun 03 '20 at 18:18

You can separate list entities by a comma like this:

//phones is a list of PhoneModel
var phoneNumbers = phones.Select(m => m.PhoneNumber)    
                    .Aggregate(new StringBuilder(),
                        (current, next) => current.Append(next).Append(" , ")).ToString();

// Remove the trailing comma and space
if (phoneNumbers.Length > 1)
    phoneNumbers = phoneNumbers.Remove(phoneNumbers.Length - 2, 2);

score -1 · Answer 15 · edited Jun 11 '21 at 01:05

-1

You can make use of google-collections.jar which has a utility class called Joiner:

String commaSepString = Joiner.on(",").join(lst);

Or you can use the StringUtils class which has a function called join. To make use of StringUtils class, you need to use common-lang3.jar

String commaSepString=StringUtils.join(lst, ',');

For reference, refer this link Convert Collection into Comma Separated String

edited Jun 11 '21 at 01:05

Peter Mortensen

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answered Nov 19 '15 at 10:39

satish

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The question was about C#, not Java. – Peter Mortensen Jun 11 '21 at 01:05

Convert a list into a comma-separated string

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