Query arraylist by LINQ (when the data type is weak)

If the data source does not implement the ienumerable <t> interface and only implements the ienumerable interface, you must specify a type for the range variable (that is, the range variable must let the compiler know what the type is)

Data source: glist
Range variable: G

Code:

1. Public class guestinfo
2. {
3. Public string name {Get; set ;}
4. Public int age {Get; set ;}
5. Public String Tel {Get; set ;}
6. Public list <string> teltable {Get; set ;}
7. }
8. Class Program
9. {
10. Static void main (string [] ARGs)
11. {
12. Arraylist Glist = new arraylist ();
13. Glist. Add (New guestinfo {name = "Qian zhuowen", age = 20, tel = "110 "});
14. Glist. Add (New guestinfo {name = "Wu Guojun", age = 21, tel = "120 "});
15. Glist. Add (New guestinfo {name = "", age = 22, tel = "130 "});
16. Glist. Add (New guestinfo {name = "monsoul", age = 23, tel = "140 "});
18. // Pay attention to the first line of the LINQ query, before G
19. VaR query = from guestinfo g in glist
20. Where G. age <22
21. Select g;
23. Foreach (var q in query)
24. {
25. Console. writeline ("Name: {0} Tel: {1}", Q. Name, Q. Tel );
26. }
28. Console. Readline ();
29. }
30. }