class Contactlnfo {
public string Name { get; set; } public string Email { get; set; }
public string Phone { get; set; }
public Contactlnfo(string n, string a, string p) {
Name = n;
Email = a;
Phone = p;
}
}
class EmailAddress {
public string Name { get; set; } public string Address { get; set; } public EmailAddress(string n, string a) {
Name = n;
Address = a;
} -
}
class SelectDemo3 { static void Main() {
Contactlnfo[] contacts = {
new Contactlnfo("", " [email protected] ", "555-1010"), new Contactlnfo("", " [email protected] ", "555-1101"), new Contactlnfo("Capa", " [email protected] ", "555-0110")
};
// EmailAddress. var emailList = from entry in contacts
Select new EmailAddress(entry.Name, entry.Email);
Console.WriteLine(" :");
// , foreach(EmailAddress in emailList)
Console.WriteLine(" {0}: {1}", e.Name, e.Address);
}
}
.
:
: [email protected] : [email protected] : [email protected]
select.
Select new EmailAddress(entry.Name, entry.Email);
EmailAddress, , Contactlnfo, contacts. , EmailAddress select .
from
- f , . from , . , from . , .
// from // , X, Y Z.
Using System; using System.Linq;
// , class ChrPair {
Public char First;
Public char Second;
public ChrPair(char c, char c2) {
First = c;
Second = c2;
}
}
class MultipleFroms { static void Main() {
char[] chrs = { 'A', 1', 'C' };
char[] chrs2 = { 'X', 1Y', 'Z' };
// from // chrs, from
// chrs2. var pairs = from chi in chrs
|
|
|
From ch2 in chrs2
Select new ChrPair(chl, ch2);
Console.WriteLine(" ABC XYZ: "); foreach(var p in pairs)
Console.WriteLine("{0} {1}", p.First, p.Second);
}
}
.
ABC XYZ:
X A Y A Z X Y Z X Y Z
ChrPair, . , chrs chrs 2, , , .
var pairs = from chi in chrs
From ch2 in chrs2
Select new ChrPair(chi, ch2);
from , chrs chrs2. chrs , chi. chrs2. from chrs2 ch2 select. select ChrPair,
, chi ch2 from. ChrPair, .
' from , . " let " .
group
group, . , , . group , , . group , . ( , , select.) group.
group _ by
, , .
group , IGrouping<TKey, TElement>, .. , System. Linq. . , , IEnumerable<IGrouping<TKey, TElement>>. IGrouping Key, , .
, group. , -, , , . org . .
|
|
|
// group.
