Join multiple strings with delimiter in C#

This article illustrates the different techniques to join multiple strings with delimiter in C#.

1. Using `String.Join()` method

A simple solution to join multiple strings with a delimiter is using the String.Join() method. It concatenates members of the specified list with the specified separator, as shown below. Note that the String.Join() method is available with .NET 4.

using System;

using System.Collections.Generic;

public class Example

{

public static void Main()

{

List<string> words = new List<string>() { "A", "B", "C" };

string str = string.Join(", ", words.ToArray());

Console.WriteLine(str); // A, B, C

}

Download Run Code

2. Using `StringBuilder`

Before .NET 4, you can use StringBuilder to join multiple strings together with a delimiter. The idea is to iterate over the list and append each encountered element to StringBuilder separated by a delimiter.

using System;

using System.Text;

using System.Collections.Generic;

public static class Extensions

{

public static string Join(this List<string> words, char delim) {

if (words.Count == 0) {

return string.Empty;

}

StringBuilder sb = new StringBuilder();

foreach (string item in words) {

sb.Append(item).Append(delim);

}

return sb.ToString().Remove(sb.Length - 1);

}

public class Example

{

public static void Main()

{

List<string> words = new List<string>() { "A", "B", "C" };

string str = words.Join(',');

Console.WriteLine(str); // A,B,C

}

Download Run Code

The above code will append the delimiter on all items except the last. Here’s an alternative solution to achieve the same:

using System;

using System.Text;

using System.Collections.Generic;

public static class Extensions

{

public static string Join(this List<string> words, string delim) {

StringBuilder sb = new StringBuilder();

string sep = string.Empty;

foreach (string item in words) {

sb.Append(sep).Append(item);

sep = delim;

}

return sb.ToString();

}

public class Example

{

public static void Main()

{

List<string> words = new List<string>() { "A", "B", "C" };

string str = words.Join(", ");

Console.WriteLine(str); // A, B, C

}

Download Run Code

That’s all about joining multiple strings together with delimiter in C#.

Join multiple strings with delimiter in C#

1. Using String.Join() method

2. Using StringBuilder

Share this:

1. Using `String.Join()` method

2. Using `StringBuilder`