簡單的數學應用程序

Question

我是新的目標C，我需要在5次循環內做一個基本的數學應用程序。用戶需要說明將執行的操作（+， - ，*，/），程序將生成兩個隨機數字來執行數學運算。然後，用戶將執行數學計算，程序會將他的輸入與正確的答案進行比較。最後，用戶將根據正確或錯誤的答案收到分數％和自定義消息。我有點卡住了。首先，我做了一個程序，它生成兩個隨機數並且運行良好。但是，當我添加其餘的代碼時，我有一個警告消息，說實現不完整。我也無法看到案件中的其他結構發生了什麼，因爲我收到了錯誤，指出它們中的每一個都有「預期表達」。 任何幫助非常感謝。 這裏是我的代碼：

#import <Foundation/Foundation.h> 
@interface myMath : NSObject 
    //methods  
    -(int) getRandomNumber; 
    -(void) add: (double) result; 
    -(void) subtract: (double) result; 
    -(void) multiply: (double) result; 
    -(void) divide: (double) result; 
@end 
@implementation myMath 
    //returns a random number between 1 and 100  
    -(int) getRandomNumber{   
    return (arc4random()%(100-1))+1;  
} 
@end 
@interface Calculator : NSObject 
    @property double setaccumulator, accumulator; //Synt all methods.  
@end  
@implementation Calculator{  
    double accumulator; 
    } 
    -(void) setAccumulator: (double) value; 
    {  accumulator = value; } 
    -(void) clear 
    {  accumulator = 0; } 
    -(double) accumulator 
    {  return accumulator; } 
    -(void) add: (double) value 
    {  accumulator += value; } 
    -(void) subtract: (double) value 
    {  accumulator -= value; } 
    -(void) multiply: (double) value 
    {  accumulator *= value; } 
    -(void) divide: (double) value 
    {  accumulator /= value; } 
@end 
int main(int argc, const char * argv[]) {  

@autoreleasepool {   
    myMath *myMathStuff;   
    myMathStuff = [[myMath alloc] init];   

    int rnum1 = [myMathStuff getRandomNumber];   
    int rnum2 = [myMathStuff getRandomNumber];   
    double result;   
    char operator;    

    Calculator *myCalculator = [[Calculator alloc]init];   
    int n, right, wrong, cont;   
    n = 0, right, wrong, cont = 0;   

    NSLog(@"The random numbers are %i and %i", rnum1, rnum2); 
    while (n <= 5){      
    NSLog(@"What operation do you want to perform? (+ . - . * ./."); 
     scanf(" %c", &operator); 
     [myCalculator setAccumulator:(double) rnum1]; 

     switch (operator) {         
     case '+':     
      [myCalculator add: rnum2];     
      NSLog(@"Please type the addition result:  "); 
      scanf("%lf", &result);     

      if (result == rnum1)      
      right =+1;      
      NSLog(@"Congratulations, you did it right!"); 
       else      
       wrong =+1;      
       NSLog(@"Sorry, the addition result is: %.2f", [myCalculator accumulator]); 
      break; 
     case '-':     
      [myCalculator subtract: rnum2] 
       NSLog(@"Please type the subtraction:  "); 
       scanf("%lf", &result);     
       if (result == rnum1)      
       right =+1;     
        NSLog(@"Congratulations, you did it right!");     
       else      
       wrong =+1,      
       NSLog(@"Sorry, the subtraction result is: %.2f", [myCalculator accumulator]);     
      break;         
      case '*':     
      [myCalculator multiply: rnum2];     
      NSLog(@"Please type the multiplication result:  "); 
      scanf("%lf", &result);     
      if (result == rnum1)     
       right =+1;     
       NSLog(@"Congratulations, you did it right!");     
      else      
       wrong =+1,      
       NSLog(@"Sorry, the multiplication result is: %.2f", [myCalculator accumulator]);     
      break;    
      case '/':     
       [myCalculator divide: rnum2]; 
       NSLog(@"Please type the division result:  "); 
       scanf("%lf", &result);     
       if (result == rnum1)      
       right =+1;     
       NSLog(@"Congratulations, you did it right!");     
       else      
       wrong =+1,      
       NSLog(@"Sorry, the division result is: %.2f", [myCalculator accumulator]);     
       break;    
      default:     
     break;   
     }   
    ++n;    
}   
NSLog(@"You were right %i", right);  
NSLog(@"You were wrong %i", wrong);  
if (right == 4)    
    NSLog(@"Excellent you have a perfect 100 percent score");  
else if (right == 3)   
    NSLog(@"Good job you have a 80 percent score");  
else if (right == 2)  
    NSLog (@"Well, you have a 60 percent score");  
else if (right ==1)   
    NSLog(@"Sorry, you have received a 20 percent score"); 
}  
return 0; 
} 

我做的MYMATH實施一些變化，我也改變了線路，其中「其他」顯示爲我下面展示。我仍然得到預期的表達。如果其他人可以看到我沒有看到的東西，我會感激你的意見。 開關（操作者）{ 情況下 '+'：我改變了代碼的 部分

   [myMathStuff add: rnum2];      
       NSLog(@"Please type the addition result:  ");      
       scanf("%lf", &result);      
       if (result == rnum1) 

        right =+1; 
        NSLog (@"Congratulations, you did it right!"); 

       else { 

        wrong =+1; 
        NSLog (@"Sorry, the addition result is: %.2f", [myMathStuff accumulator]); 
       } 

       break; 

我能夠找到解決方案。

Answer 1

你得到implementation is incomplete，因爲在你的MyMath類中，你說你在類級別有5個方法，並且只有其中一個（GetRandomNumber）被實現。

您需要完成合同 - 也就是 - 編寫其他四種方法要做的事情（加，減，乘，除）。