String vs StringBuilder Difference - C#

Introduction :

In this post i am going to explain the difference between String and String Builder in C#. This is a common interview question.

String

String is immutable.Immutable means once we create string object we cannot modify. Any operation like insert, replace or append happened to change string simply it will discard the old value and it will create new instance in memory to hold the new value.

Program

Using System;

public static void Main()
{
  string myString = "Difference";
  myString += " between";
  myString += " String";
  myString += " and";
  myString += " StringBuilder";
}

StringBuilder

String builder is mutable it means once we create string builder object we can perform any operation like insert, replace or append without creating new instance for every time.

Program

Using System.Text;

public static void Main()
{
  StringBuilder myString = new StringBuilder("Difference");
  myString.Append(" between")
  myString.Append(" String")
  myString.Append(" and")
  myString.Append(" StringBuilder")
}

For better understanding see the below table and image

                                   !********************* Hope you understand the difference J ***************************!

Reference:

http://www.aspdotnet-suresh.com & Venkat's csharp-video-tuotrials.blogspot.co.uk