using System;
public class MyString {
private string fString;
public MyString() {
fString = “”;
}
public MyString(string inStr) {
fString = inStr;
}
public string ToStr() {
return fString;
}
public string Right(int nChars) {
if (nChars > fString.Length)
return fString;
string s = “”;
for (int i = fString.Length – nChars; i < fString.Length; ++i)
s += fString[i];
return s;
}
public string Left(int nChars) {
if (nChars > fString.Length)
return fString;
string s = “”;
for (int i = 0; i < nChars; ++i)
s += fString[i];
return s;
}
public string Mid(int nStart, int nEnd) {
if (nStart < 0 || nEnd > fString.Length)
return fString;
if (nStart > nEnd)
return “”;
string s = “”;
for (int i = nStart; i < nEnd; ++i)
s += fString[i];
return s;
}
}
class Class1 {
static void Main(string[] args) {
MyString s = new MyString("Hello world");
System.Console.WriteLine("s = {0}", s.ToStr());
System.Console.WriteLine("Right 3 = [{0}]", s.Right(3));
System.Console.WriteLine("Left 6 = [{0}]", s.Left(6));
System.Console.WriteLine("Mid 2,4 = [{0}]", s.Mid(2, 4));
}
}
[/csharp]