如何將對象添加到Objective-C中的數組？

Question

我開始在Objective-C中編程。我正在使用一本書來學習第一本基礎知識。給出的例子不起作用！我在代碼中看不到問題。
這不是很難理解它，但它不會工作。但是我在別處找到的所有東西，他們像我一樣添加了對象。
我不知道語法是否改變了？我正在使用iOS 4.3 SDK和Xcode 3.2.6！
這部分失敗：

[questions addObject: @」What is 7 + 7?」]; //FAILS 
[answers addObject: @」14」]; 

該錯誤消息表示：
/Applications/Quiz/Classes/QuizAppDelegate.m:32:0
應用/測驗/類別/ QuizAppDelegate.m：32：錯誤： '@'令牌之前的預期表達式

如果有人能幫助我，我會非常高興！ 謝謝！

我附上了代碼！

朱

全碼：.H：

#import <UIKit/UIKit.h> 

@interface QuizAppDelegate : NSObject <UIApplicationDelegate> { 

    int currentQuestionIndex; 

    //The model objects 
    NSMutableArray *questions; 
    NSMutableArray *answers; 

    //The view objects 
    IBOutlet UILabel *questionField; 
    IBOutlet UILabel *answerField; 

    UIWindow *window; 
} 

@property (nonatomic, retain) IBOutlet UIWindow *window; 

-(IBAction)showQuestion:(id)sender; 
-(IBAction)showAnswer:(id)sender; 

@end 

部分代碼而失敗：.M：

#import "QuizAppDelegate.h" 

@implementation QuizAppDelegate 

@synthesize window; 

-(id)init{ 

    // Call the init method implemented by the superclass 
    [super init]; 

    // Create two arrays and make the pointers point to them 
    questions = [[NSMutableArray alloc] init]; 
    answers = [[NSMutableArray alloc] init]; 

    // Add questions and answers to the arrays 
    [questions addObject: @」What is 7 + 7?」]; //FAILS 
    [answers addObject: @」14」]; 

    [questions addObject: @」Was ist die Hauptstadt von Madagaskar?」]; //FAILS 
    [answers addObject: @」Antananarivo」]; 

    [questions addObject: @」Was ergibt 5-2*2+6?」]; //FAILS 
    [answers addObject: @」7」]; 

    // Return the address of the new object 
    return self; 

} 

-(IBAction)showQuestion:(id)sender{ 

//Step to the next question 
currentQuestionIndex++; 

//Am I past the last question? 
if(currentQuestionIndex==[questions count]){ 

    //Go back to the first question 
    currentQuestionIndex=0; 
} 

// Get the string at that index in the questions array 
NSString *question = [questions objectAtIndex:currentQuestionIndex]; 

//Log the string to the console 
NSLog(@"displaying question:%@",question); 

//Display the string in the question field 
[questionField setText:question]; 

//Clear the answer field 
[answerField setText:@"???"]; 
} 

-(IBAction)showAnswer:(id)sender{ 

//What is the answer to the current question 
NSString *answer=[answers objectAtIndex:currentQuestionIndex]; 

//Display it in the answer field 
[answerField setText:answer]; 
} 

Answer 1

我認爲，你使用雙引號的假字符「，因爲你的是」。你是否從某處複製並粘貼了代碼？

Answer 2

或者更短：

[myArray addObject:[NSString stringWithString:@"Wie hoch ist der Eiffelturm?"]];