C# tutorial-Substring method

C# String manipulation

Substring() method

The Substring(start_pos, [length]) method can be used to cut out a substring with the number of characters specified by length argument from a string by taking from the start_pos argument. The length argument is optional. If you do not specify this argument the substring will contain characters by starting from the character specified by the start argument to the last character of the string.

Example:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
  strmanip();
  Console.ReadLine();
}

static void strmanip(){
  string st = "C# programming or Csharp programming";
  string subst = st.Substring(0, 2);
  Console.WriteLine("{0}", subst);



                }

      }

}

For another example, we use the Substring() and IndexOf() methods to validate an e-mail address. The e-mail is valid if it contains the @ and . characters. The valid . character is the . character that stays after the @ character in he email string.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
strmanip();
test();
Console.ReadLine();
}

static void strmanip(){
string email="";
string subemail="";
Console.Write("Enter your e-mail address:");
email=Console.ReadLine();
int pos = email.IndexOf('@');
if(pos!=-1)
subemail = email.Substring(email.IndexOf('@'));
if (subemail.IndexOf('.')!=-1) Console.WriteLine("Valid e-maild address!");

else Console.WriteLine("Invalid e-mail address!");


    }
  }
}