Convert array of integers to comma-separated string

Question

It's a simple question; I am a newbie in C#, how can I perform the following

I want to convert an array of integers to a comma-separated string.

I have

int[] arr = new int[5] {1,2,3,4,5};

I want to convert it to one string

string => "1,2,3,4,5"

score 647 · Accepted Answer · edited May 31 '13 at 18:34

647

var result = string.Join(",", arr);

This uses the following overload of string.Join:

public static string Join<T>(string separator, IEnumerable<T> values);

edited May 31 '13 at 18:34

Gibron

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answered Jan 21 '11 at 07:56

Cheng Chen

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You do not need to pass the explicit generic argument in this case. It will be inferred. – leppie Jan 21 '11 at 07:59
7

Pre .NET 4 string.Join(",", Array.ConvertAll(arr, i => i.ToString())) – TPAKTOPA Dec 12 '14 at 14:06
Is there a simple way to do the reverse of this? Take the string and put it into an array? – Kory Mar 11 '15 at 15:13
4

@Kory: Using String.Split method, see https://msdn.microsoft.com/en-us/library/system.string.split(v=vs.110).aspx – Cheng Chen Mar 12 '15 at 06:11

score 151 · Answer 2 · answered Jan 21 '11 at 07:56

151

.NET 4

string.Join(",", arr)

.NET earlier

string.Join(",", Array.ConvertAll(arr, x => x.ToString()))

answered Jan 21 '11 at 07:56

leppie

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Thanks for the pre-.NET4 version! – kdenney Dec 15 '11 at 17:50
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just realized i couldn't use the .net 4 version and i didn't understood why i was having an error until i saw your answer , thanks. – Luis Tellez May 21 '13 at 21:17
I am using .NET 4.5. I tried to concat the comma separated numbers with a string. I got an error saying "cannot convert string[] to char". So the earlier version worked flawlessly. – Prasanth G Jan 30 '20 at 12:49

score 16 · Answer 3 · edited May 28 '16 at 07:14

16

int[] arr = new int[5] {1,2,3,4,5};

You can use Linq for it

String arrTostr = arr.Select(a => a.ToString()).Aggregate((i, j) => i + "," + j);

edited May 28 '16 at 07:14

AlanT

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answered May 28 '16 at 05:44

Manish Nayak

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score 7 · Answer 4 · answered May 31 '13 at 19:07

You can have a pair of extension methods to make this task easier:

public static string ToDelimitedString<T>(this IEnumerable<T> lst, string separator = ", ")
{
    return lst.ToDelimitedString(p => p, separator);
}

public static string ToDelimitedString<S, T>(this IEnumerable<S> lst, Func<S, T> selector, 
                                             string separator = ", ")
{
    return string.Join(separator, lst.Select(selector));
}

So now just:

new int[] { 1, 2, 3, 4, 5 }.ToDelimitedString();

score 3 · Answer 5 · edited Aug 18 '13 at 15:01

3

Use LINQ Aggregate method to convert array of integers to a comma separated string

var intArray = new []{1,2,3,4};
string concatedString = intArray.Aggregate((a, b) =>Convert.ToString(a) + "," +Convert.ToString( b));
Response.Write(concatedString);

output will be

1,2,3,4

This is one of the solution you can use if you have not .net 4 installed.

edited Aug 18 '13 at 15:01

Guido Preite

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answered Aug 18 '13 at 14:42

sushil pandey

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It performs poorly due to the string concatenation, though – Simon Belanger Aug 18 '13 at 15:04
yes it will perform poorly but before .net 4.0 String.join only take string array as parameter.Thus in that case we also need to convert in string .we can use ToString it perform better but there is problem of null exception – sushil pandey Aug 20 '13 at 17:54

Convert array of integers to comma-separated string

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