C# as operator
as operator 係用黎做 casting 的
static void Main()
{
double x = 1234.7;
int a;
// Cast double to int.
a = (int)x;
System.Console.WriteLine(a);
}
// Output: 1234
如果用 boxing 黎轉 type 既話, 錯 type 的話就會 throw InvalidCastException, 但如果用 as operator 就唔會 throw InvalidCastException, 而 value 就會係 null
public static void Main()
{
object time1 = DateTime.Now;
DateTime? t = time1 as DateTime?; // valid casting
int? wrongCast = time1 as int?; // wrongCast == null
}
Tags: c#
