using System;

using System.Linq;

using System.Collections.Generic;

using System.Text;

​

/* https://github.com/dotnet/samples/blob/master/snippets/csharp/how-to/strings/Concatenate.cs */

namespace HowToStrings

{

    static public class Concatenate

    {

        public static void Examples()

        {

            UsingAddWithConstantStrings();

            UsingAddWithVariables();

            UsingInterpolationWithVariables();

            UsingStringBuilder();

            UsingConcatAndJoin();

            UsingAggregate();

        }

​

        private static void UsingAddWithConstantStrings()

        {

            // <Snippet1>

            // Concatenation of literals is performed at compile time, not run time.

            string text = "Historically, the world of data and the world of objects " +

            "have not been well integrated. Programmers work in C# or Visual Basic " +

            "and also in SQL or XQuery. On the one side are concepts such as classes, " +

            "objects, fields, inheritance, and .NET Framework APIs. On the other side " +

            "are tables, columns, rows, nodes, and separate languages for dealing with " +

            "them. Data types often require translation between the two worlds; there are " +

            "different standard functions. Because the object world has no notion of query, a " +

            "query can only be represented as a string without compile-time type checking or " +

            "IntelliSense support in the IDE. Transferring data from SQL tables or XML trees to " +

            "objects in memory is often tedious and error-prone.";

​

            System.Console.WriteLine(text);

            // </Snippet1>

        }

​

        private static void UsingAddWithVariables()

        {

            // <Snippet2>

            string userName = "<Type your name here>";

            string dateString = DateTime.Today.ToShortDateString();

​

            // Use the + and += operators for one-time concatenations.

            string str = "Hello " + userName + ". Today is " + dateString + ".";

            System.Console.WriteLine(str);

​

            str += " How are you today?";

            System.Console.WriteLine(str);

            // </Snippet2>

        }

        private static void UsingInterpolationWithVariables()

        {

            // <Snippet3>

            string userName = "<Type your name here>";

            string date = DateTime.Today.ToShortDateString();

​

            // Use string interpolation to concatenate strings.

            string str = $"Hello {userName}. Today is {date}.";

            System.Console.WriteLine(str);

​

            str = $"{str} How are you today?";

            System.Console.WriteLine(str);

            // </Snippet3>

        }

​

        private static void UsingStringBuilder()

        {

            // <Snippet4>

            // Use StringBuilder for concatenation in tight loops.

            var sb = new System.Text.StringBuilder();

            for (int i = 0; i < 20; i++)

            {

                sb.AppendLine(i.ToString());

            }

            System.Console.WriteLine(sb.ToString());

            // </Snippet4>

        }

​

        private static void UsingConcatAndJoin()

        {

            // <Snippet5>

            string[] words = { "The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog." };

​

            var unreadablePhrase = string.Concat(words);

            System.Console.WriteLine(unreadablePhrase);

​

            var readablePhrase = string.Join(" ", words);

            System.Console.WriteLine(readablePhrase);

            // </Snippet5>

        }

​

        private static void UsingAggregate()

        {

            // <Snippet6>

            string[] words = { "The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog." };

​

            var phrase = words.Aggregate((partialPhrase, word) =>$"{partialPhrase} {word}");

            System.Console.WriteLine(phrase);

            // </Snippet6>

        }

    }

}