如何将对象添加到Objective-C中的数组？

Question

我开始在Objective-C中编程。我正在使用一本书来学习第一本基础知识。给出的例子不起作用！我在代码中看不到问题。
这不是很难理解它，但它不会工作。但是我在别处找到的所有东西，他们像我一样添加了对象。
我不知道语法是否改变了？我正在使用iOS 4.3 SDK和Xcode 3.2.6！
这部分失败：

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

该错误消息表示：
/Applications/Quiz/Classes/QuizAppDelegate.m:32:0
应用/测验/类别/ QuizAppDelegate.m：32：错误： '@'令牌之前的预期表达式

如果有人能帮助我，我会非常高兴！ 谢谢！

我附上了代码！

朱

全码：.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 

部分代码而失败：.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

我认为，你使用双引号的假字符“，因为你的是”。你是否从某处复制并粘贴了代码？

Answer 2

或者更短：

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