Question

please consider this code :

1-...
2-{
  3-...
  4-SqlConnection cn=new SqlConnection();
  5-... 
6-}

if program reach to statement No.6 will cn dispose? if not what happend for cn variable?

Answer 1

if program reach to statement No.6 will cn dispose?

No.

if not what happend for cn variable?

It depends whether you use it afterwards. If you don’t use it and it falls out of scope which means that it is eligible for garbage collections. When this garbage collection happens is out of your control. But when it happens the destructor will be invoked which itself calls the Dispose method.

This being said the correct approach is to always wrap IDisposable resources in using statements. This ensures that the Dispose method will always be called, even if an exception is thrown:

2-{
  3-...
  4-using (SqlConnection cn=new SqlConnection())
    {
        ...
    }
    5-... 
6-}