iphone - Find location of specific character in NSString -

how can find location of specific character in nsstring?

i have tried returns empty range (i want find location of '?'):

nsrange range = [@"this ? test see if works" rangeofcharacterfromset:[nscharacterset charactersetwithcharactersinstring:@"?"]]; 

you must doing else wrong. because absolutely correct , returns {10, 1}. @ least on mac ;-)