幫我的NSDictionary問題

Question

當我跑我下面的代碼它顯示我像下面

警告一個錯誤：「的NSMutableDictionary」可不迴應「-setObject：forKey：forKey：」

什麼問題在我的代碼中。

myNumberOfPlayers = players; 

myDifficultyLevel = difficulty; 

myDuration = duration; 

myExcerciseId = excerciseId; 

NSMutableDictionary *myDictionary = [[ NSMutableDictionary alloc] init]; 
    [ myDictionary setObject:players forKey:players forKey:@"no_of_players"]; 
    [ myDictionary setObject:difficulty forKey:@"difficulty_level"]; 
    [ myDictionary setObject:duration forKey:@"duration_excercise"]; 
    [ myDictionary setObject:excerciseId forKey:@"Excercise_id"]; 

Answer 1

它應該是

[myDictionary setObject:players forKey:@"no_of_players"]; 

代替

[myDictionary setObject:players forKey:players forKey:@"no_of_players"]; 

Answer 2

您正在調用一個不存在的方法。 你應該試試這個：

[ myDictionary setObject:players forKey:players ] 

或本

[ myDictionary setObject:players forKey:@"no_of_players"] 

我敢打賭，第二個選擇是正確的。您的代碼中可能存在拼寫錯誤，並且意外地重複了players變量。

字典可以爲確定的鍵設置對象。在同一個調用中設置一個對象給出兩個不同的鍵是沒有意義的。

Answer 3

此代碼必須像

NSMutableDictionary *myDictionary = [[ NSMutableDictionary alloc] init]; 
[myDictionary setObject:players forKey:@"no_of_players"];//you cant call for key two time. 
[myDictionary setObject:difficulty forKey:@"difficulty_level"]; 
[myDictionary setObject:duration forKey:@"duration_excercise"]; 
[myDictionary setObject:excerciseId forKey:@"Excercise_id"]; 

Answer 4

的NSMutableDictionary * myDictionary = [[ALLOC的NSMutableDictionary] INIT];

[ myDictionary setObject:players forKey:@"no_of_players"]; 
[ myDictionary setObject:difficulty forKey:@"difficulty_level"]; 
[ myDictionary setObject:duration forKey:@"duration_excercise"]; 
[ myDictionary setObject:excerciseId forKey:@"Excercise_id"];