Program.cs

using System;
using System.Linq;
using System.Globalization;
using System.Collections.Generic;
using StringStrtrExtension;

namespace StrtrApp
{
    class Program
    {
        public static void Main(string[] args)
        {

            Console.WriteLine();
            string input = "baab";
            string output = input.StrTr("ab", "ba");

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            input = "hallodrihallodra";
            output = input.StrTr(("dri", "dra"), ("dra", "dri"));

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            var kvpdict = new Dictionary<string, string>()
            {
                {"hallo", "hi"},
                {"dri", "dra"},
                {"dra", "drix"}
            };

            output = input.StrTr(kvpdict);

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            var tupleList = new List<(string, string)>
            {
                ("hallo", "cow"),
                ("Dri", "chicken"),
                ("RA", "dog")
            };
            output = input.StrTr(tupleList, StringComparison.OrdinalIgnoreCase);

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            output = input.StrTr(tupleList, false);

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            var tupleArray = new (string, string)[]
            {
                ("hallo", "cow"),
                ("Dri", "chicken"),
                ("RA", "dog")
            };
            output = input.StrTr(tupleArray, StringComparison.OrdinalIgnoreCase);

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            output = input.StrTr(tupleArray, false, CultureInfo.CurrentCulture);

            Console.WriteLine("input: {0}, output: {1}", input, output);
            Console.WriteLine();

            var animals = "dogcathorsecow";
            var animalsReplace = animals.Replace("dog", "cat").Replace("cat", "horse").Replace("horse", "cow").Replace("cow", "bird");
            var animalsStrTr = animals.StrTr(("dog", "cat"), ("cat", "horse"), ("horse", "cow"), ("cow", "bird"));

            Console.WriteLine("animalsReplace: {0}", animalsReplace);
            Console.WriteLine("animalsStrTr: {0}", animalsStrTr);
            Console.WriteLine();

            Console.WriteLine("\nExamples from the PHP manual:");

            Console.WriteLine("\nExample #1 strtr() example");
            input = "Bäfoo Dåbar Söderström";
            Console.WriteLine(input+" => "+input.StrTr("äåö", "aao"));

            Console.WriteLine("\nExample #2 example with two arguments");
            input = "hi all, I said hello";
            var trans = new (string, string)[]
            {
                ("hello", "hi"),
                ("hi", "hello")
            };
            Console.WriteLine(input+" => "+input.StrTr( trans));
            
            Console.WriteLine("\nExample #3 behavior comparison");
            input = "baab";
            Console.WriteLine(input+" => "+input.StrTr("ab", "01"));
            Console.WriteLine(input+" => "+input.StrTr( ("ab", "01") ));
            Console.WriteLine();

        }
    }
}