I m curious why would i use string formatting while i can use concatenation such as
Console.WriteLine(\"Hello {0} !\", name);
Console.WriteLine(\"Hello \"+
In addition to reasons like Ignacio's, many (including me) find String.Format-based code much easier to read and alter.
string x = String.Format(
"This file was last modified on {0} at {1} by {2}, and was last backed up {3}."
date, time, user, backupDate);
vs.
string x = "This file was last modified on " + date + " at "
+ time + " by " + user + " and was last backed up " + backupDate + ".";