A throw statement (15.9.5) throws an exception immediately and unconditionally. Control never reaches the statement immediately following the throw.
Certain exceptional conditions that arise during the processing of C# statements and expression cause an exception in certain circumstances when the operation cannot be completed normally. For example, an integer division operation (14.7.2) throws a System.DivideByZeroException if the denominator is zero. See 23.4 for a list of the various exceptions that can occur in this way.