Question

Possible Duplicates:
Direct casting vs 'as' operator?
Casting: (NewType) vs. Object as NewType

What is difference between normal typecasting and using “AS” keyword?

Answer 1

Using as will fail gracefully if the object is the wrong type, and the resulting value will be null, where a normal cast would throw an InvalidCastException:

object x = new object();
string y = x as string; // y == null
string z = (string)x; // InvalidCastException