The - operator can function as either a unary or a binary operator.
Unary - operators are predefined for all numeric types. The result of a unary - operation on a numeric type is the negation of the operand.
Binary - operators are predefined for all numeric and enumeration types to subtract the second operand from the first.
Delegate types also provide a binary - operator, which performs delegate removal.
User-defined types can overload the unary – and binary - operators (see operator).
using System; class Test { public static void Main() { int a = 5; Console.WriteLine(-a); Console.WriteLine(a - 1); Console.WriteLine(a - .5); } }
-5 4 4.5
C# Operators | CLR 7.6.2 Unary minus operator | CLR 7.7.5 Subtraction operator