C# Language Specification

Causes of exceptions

Exception can be thrown in two different ways.

• 
  A throw statement (§8.9.5) 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 (§7.8.2) throws a System.DivideByZeroException if the denominator is zero. See §16.4 for a list of the various exceptions that can occur in this way.
  

2.