的NSMutableDictionary選擇的setObject forkey錯誤

Question

這裏是我的代碼

NSMutableDictionary* stations = [[NSMutableDictionary alloc] init]; 
RadioStation* newStation; 
newStation = [[RadioStation alloc] 
initWithName:@"Star 94 fm" atfrequency:91.4]; 
[stations setObject:newStation forkey:@"WSTR"]; 

，但我不斷收到一個錯誤："no visible @interface" for NSMutableDictionary declares the selector setObject forkey

任何幫助將不勝感激。

Answer 1

正確的選擇器是setObject:forKey:而不是setObject:forkey:。