How to determine the order of exception handling using catch blocks in code?

In C#, the order of exception handling with catch blocks is determined by the sequence in which they are declared. When an exception occurs, the system goes through the catch blocks from top to bottom and selects the first one that matches the exception type.

Important:

• More specific exceptions should come before more general ones, otherwise they will never be reached.
• For example, first catch ArgumentNullException, then the general Exception.

Example:

try
{
    // code that may throw an exception
}
catch (ArgumentNullException ex)
{
    // handle specific exception
}
catch (Exception ex)
{
    // handle all other exceptions
}

If you change the order of catch, for example, first Exception, then ArgumentNullException, the second block will become unreachable, and the compiler will generate an error.