C# 0 The Complete Reference

string

’s methods: 

Substring( )

. The 

Substring( )

 method returns a new string that contains 

a specified portion of the invoking string. Because a new 

string

 object is manufactured that 

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contains the substring, the original string is unaltered, and the rule of immutability is still 

intact. The form of 

Substring( )

 that we will be using is shown here:

string Substring(int 

start

, int 

len

)

Here, 

start

 specifies the beginning index, and 

len

 specifies the length of the substring.

Here is a program that demonstrates 

Substring( )

 and the principle of immutable strings:

// Use Substring().

using System;

class SubStr {

  static void Main() {

    string orgstr = "C# makes strings easy.";

    // construct a substring

    string substr = orgstr.Substring(5, 12);

    Console.WriteLine("orgstr: " + orgstr);

    Console.WriteLine("substr: " + substr);

  }

}

Here is the output from the program:

orgstr: C# makes strings easy.

substr: kes strings

As you can see, the original string