[C#] 문자열 함수

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace ConsoleApplication9
{
    class StringTest2
    {
        static void Main(string[] args)
        {
            string str = "Hello Wourld Hi Hello";
            Console.WriteLine("원문 str: {0}", str);
            Console.WriteLine();
            Console.WriteLine("Index of \"World\": {0}", str.IndexOf("World"));
            Console.WriteLine("LastIndexOf \"Hi\": {0}", str.LastIndexOf("World"));
            Console.WriteLine("Replace\"World\" to \"Tom\" :{0}", str.Replace("World","Tom"));
 
            Console.WriteLine("str의 substring(6): {0} ", str.Substring(6));
 
        }
    }
}