C# 0 The Complete Reference

select

 clause:

select entry.Address;

Instead of returning the entire range variable, it returns only the 

Address

 portion. This 

fact is evidenced by the output. This means the query returns a sequence of strings, not a 

sequence of 

EmailAddress

 objects. This is why the 

foreach

 loop specifies 

s

 as a 

string

. As 

explained, the type of sequence returned by a query is determined by the type of value 

returned by the 

select

 clause.

One of the more powerful features of 

select

 is its ability to return a sequence that contains 

elements created during the execution of the query. For example, consider the following 

program. It defines a class called 

ContactInfo

, which stores a name, e-mail address, and 

telephone number. It also defines the 

EmailAddress

 class used by the preceding example. 

Inside