String Vs StringBuilder

String :

ex:

string returnNumber = "";
for(int i = 0; i<1000; i++)
{
    returnNumber = returnNumber + i.ToString();
}


1.String object is immutable
2.Data value maynot be Changed and Variable value may be changed.


StringBuilder:


ex:
StringBuilder returnNumber = new StringBuilder(10000);
for(int i = 0; i<1000; i++)
{
    returnNumber.Append(i.ToString());
}

1.StringBuilder objects are mutable 

2.StringBuilder performs is faster than Strings

Advantage of StringBuilder:

StringBuilder  is the best way to concatenate string.it doesnt take any time to concatenate string compare to normal string concatenate.you can concanate a string by using Append()  as follows

example:

           StringBuilder sb1 = new StringBuilder("Shakeer ");

           sb1.Append  ("Hussain ");

           Console.WriteLine(sb1.ToString());

output :ShakeerHussain