C# Convert List to String

Use the string.Join method and StringBuilder to convert Lists and strings.

Convert List, string. Think of a sentence. It contains some words. We could represent a sentence as a single string—one with spaces. But a list of strings (of words) is sometimes better.

We can convert our string into a List of smaller strings. For the reverse, we can convert our List into a string. This is possible with the ToArray method on the List type.Convert

First example. We use the string.Join method to combine a List of strings into one string. The output can be used as a CSV record. On new .NET Framework versions, ToArray is not required.Join

However: In previous versions, we had to call ToArray on a List before using Join. In older programs this is still required.

C# program that converts List using System; using System.Collections.Generic; class Program { static void Main() { List<string> dogs = new List<string>(); dogs.Add("Aigi"); // Add string 1 dogs.Add("Spitz"); // 2 dogs.Add("Mastiff"); // 3 dogs.Add("Finnish Spitz"); // 4 dogs.Add("Briard"); // 5 string dogCsv = string.Join(",", dogs.ToArray()); Console.WriteLine(dogCsv); } } Output Aigi,Spitz,Mastiff,Finnish Spitz,Briard

Example 2. Here we use the StringBuilder class to convert a List to a single string. Note that you can convert a List of any object type into a string this way.StringBuilder

Final delimiter: The example has a final delimiter on the end. This is not present in code that uses string.Join. It can be inconvenient.

TrimEnd: Sometimes, it is good to remove the end delimiter with TrimEnd. Other times it is best left alone.

TrimEnd, TrimStart

C# program that uses List and StringBuilder using System; using System.Collections.Generic; using System.Text; class Program { static void Main() { List<string> cats = new List<string>(); // Create new list of strings cats.Add("Devon Rex"); // Add string 1 cats.Add("Manx"); // 2 cats.Add("Munchkin"); // 3 cats.Add("American Curl"); // 4 cats.Add("German Rex"); // 5 StringBuilder builder = new StringBuilder(); foreach (string cat in cats) // Loop through all strings { builder.Append(cat).Append("|"); // Append string to StringBuilder } string result = builder.ToString(); // Get string from StringBuilder Console.WriteLine(result); } } Output Devon Rex|Manx|Munchkin|American Curl|German Rex|

Example 3. Here we convert a List of ints into a single string. The StringBuilder's Append method receives a variety of types. We can simply pass it the int.

And: Append() will handle the int on its own. It will convert it to a string and append it.

Performance: StringBuilder is fast for most programs. More speed could be acquired by using a char[] and then converting to a string.

Char Array

C# program that converts List types using System; using System.Collections.Generic; using System.Text; class Program { static void Main() { List<int> safePrimes = new List<int>(); // Create list of ints safePrimes.Add(5); // Element 1 safePrimes.Add(7); // Element 2 safePrimes.Add(11); // Element 3 safePrimes.Add(23); // Element 4 StringBuilder builder = new StringBuilder(); foreach (int safePrime in safePrimes) { // Append each int to the StringBuilder overload. builder.Append(safePrime).Append(" "); } string result = builder.ToString(); Console.WriteLine(result); } } Output 5 7 11 23

Example 4. Finally, we get a List of strings from a string in CSV format. This requires the Split method. If you require per-item conversion, loop over the string array returned by Split.

C# program that converts string to List using System; using System.Collections.Generic; class Program { static void Main() { string csv = "one,two,three"; // The input string string[] parts = csv.Split(','); // Call Split method List<string> list = new List<string>(parts); // Use List constructor foreach (string item in list) { Console.WriteLine(item); } } } Output one two three

A summary. We converted Lists and strings using the string.Join methods and the StringBuilder approach. The List is easily concatenated and stored in a database or file with these methods.List Strings

The Dev Codes

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

TheDeveloperBlog.com

C# Convert List to String

Related Links:

.Net

Java

Related Links