Thursday, July 10, 2014

Difference Between String And String Builder?

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.


string str = "hi";
// create a new string instance instead of changing the old one
str += "test";
str += "help";

String Builder

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.


StringBuilder sb = new StringBuilder("");

sb.Append("hi");
sb.Append("test ");
string str = sb.ToString();


Differences


String
StringBuilder
It’s an immutable
It’s mutable
Performance wise string is slow because every time it will create new instance
Performance wise stringbuilder is high because it will use same instance of object to perform any action
In string we don’t have append keyword
In StringBuilder we can use append keyword
String belongs to System namespace
Stringbuilder belongs to System.Text namespace