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?

Solution 1

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.

Solution 2

You can use String.Join method to combine items:

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

Solution 3

Using String.Join:

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

Using LINQ aggregation:

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

Solution 4

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!

Solution 5

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()));

View more solutions

Comments

[asawyer]

String.Join is all you need.

[Mithrandir]

var csvString = String.Join(",", lst); should do it.

[Tim Schmelter]

For anyone who wants to reopen this, if it's not too localized it's a duplicate: stackoverflow.com/questions/799446/…

[Peter Mortensen]

Similar (from 2008): How can I join int[] to a character-separated string in .NET?

[Anton]

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.

[Hari]

I have list of type int32. when I use aggregate function you mentioned, it says "Cannot convert lambda expression to delegate type 'System.Func<int,int,int>' 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'"

[bets]

@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);

[Rani Radcliff]

this does not work for me. It produces the name of the collection rather than the objects in the list.

[Peter Mortensen]

The question was about C#, not Java.

[Peter Mortensen]

This is essentially identical to the accepted answer from 2013.

[Peter Mortensen]

From what C# version is this valid?

[Hans Kesting]

Is this Javascript? (the question is about C#)