C# program to convert a list of characters into a string

Converting a list of characters into a string is a common operation in C#. There are several approaches to accomplish this task, each suitable for different scenarios and data structures.

Syntax

Following are the main syntax patterns for converting characters to strings −

// Using string constructor with char array
string result = new string(charArray);

// Using string.Join() method
string result = string.Join("", charList);

// Using StringBuilder class
StringBuilder sb = new StringBuilder();
sb.Append(charArray);
string result = sb.ToString();

Using String Constructor with Character Array

The most direct approach is using the string constructor that accepts a character array −

using System;

class Program {
   static void Main(string[] args) {
      char[] ch = new char[5];
      ch[0] = 'H';
      ch[1] = 'e';
      ch[2] = 'l';
      ch[3] = 'l';
      ch[4] = 'o';
      
      string myChar = new string(ch);
      Console.WriteLine("Converted to string = " + myChar);
   }
}

The output of the above code is −

Converted to string = Hello

Using string.Join() Method

When working with a List<char> or other collections, string.Join() provides a flexible solution −

using System;
using System.Collections.Generic;

class Program {
   static void Main(string[] args) {
      List<char> charList = new List<char> {'W', 'o', 'r', 'l', 'd'};
      
      string result = string.Join("", charList);
      Console.WriteLine("Converted to string = " + result);
      
      // Alternative: convert to array first
      char[] charArray = charList.ToArray();
      string result2 = new string(charArray);
      Console.WriteLine("Using array conversion = " + result2);
   }
}

The output of the above code is −

Converted to string = World
Using array conversion = World

Using StringBuilder for Large Collections

For performance with large character collections, StringBuilder is the optimal choice −

using System;
using System.Collections.Generic;
using System.Text;

class Program {
   static void Main(string[] args) {
      List<char> charList = new List<char> {'C', '#', ' ', 'P', 'r', 'o', 'g', 'r', 'a', 'm'};
      
      StringBuilder sb = new StringBuilder();
      foreach (char c in charList) {
         sb.Append(c);
      }
      
      string result = sb.ToString();
      Console.WriteLine("Using StringBuilder = " + result);
      Console.WriteLine("Length: " + result.Length);
   }
}

The output of the above code is −

Using StringBuilder = C# Program
Length: 10

Comparison of Methods

Conclusion

Converting character collections to strings in C# can be accomplished using string constructors for arrays, string.Join() for collections, or StringBuilder for performance-critical scenarios. Choose the method based on your data structure and performance requirements.