static void TestCasting() { int i = 10; float f = 0; f = i; // An implicit conversion, no data will be lost. f = 0.5F; i = (int)f; // An explicit conversion. Information will be lost. }
A cast explicitly invokes the conversion operator from one type to another. The cast will fail if no such conversion operator is defined. You can write custom conversion operators to convert between user-defined types. For more information about defining a conversion operator, see explicit (C# Reference) and implicit (C# Reference).
The following program casts a double to an int. The program will not compile without the cast.
class Test { static void Main() { double x = 1234.7; int a; a = (int)x; // cast double to int System.Console.WriteLine(a); } }