c# - Is one of these for loops faster than the other? -

for (var keyvalue = 0; keyvalue < dwhsessiondto.keyvalues.count; keyvalue++) {...}   var count = dwhsessiondto.keyvalues.count; (var keyvalue = 0; keyvalue < count; keyvalue++) {...} 

i know there's difference between two, 1 of them faster other? think second faster.

yes, first version much slower. after all, i'm assuming you're dealing types this:

public class slowcountprovider {     public int count     {                 {             thread.sleep(1000);             return 10;         }     } }  public class keyvalueswithslowcountprovider {     public slowcountprovider keyvalues     {         { return new slowcountprovider(); }     } } 

here, first loop take ~10 seconds, whereas second loop take ~1 second.

of course, might argue assumption you're using code unjustified - point right answer depend on types involved, , question doesn't state types are.

now if you're actually dealing type accessing keyvalues , count cheap (which quite likely) wouldn't expect there difference. mind you, i'd prefer use foreach possible:

foreach (var pair in dwhsessiondto.keyvalues) {     // use pair here } 

that way never need count. then, haven't said you're trying inside loop either. (hint: more useful answers, provide more information.)