這個c + +代碼有什麼問題

Question

我是一個初學者的學習代碼，我正在複製什麼YouTube編程教學視頻說。但是當我編寫代碼時，會導致一些錯誤。

下面的代碼：

#include <iostream> 
using namespace std; 
int main() 
{ 
    int num1 , num2; 

    cout<< " Enter number 1 and number 2 \n"; 
    cin>> num1 >> num2; 

    if (num1 == num2); 
     cout<< "The both numbers are equal \n"; 

    else if (num1> num2) 
     cout<< "Number 1 is greater than number 2 \n"; 
    else (num1< num2) 
     cout<< "Number 2 is greater than number 1 \n"; 

    return 0; 
} 

Answer 1

注意;意味着表達結束，所以你應該改變

if (num1 == num2); 

到

if (num1 == num2) 

而且else不需要條件，所以改變

else (num1< num2) 

到

else 

Answer 2

1. 你不需要;後if條件檢查

2. 如果你想要做一個健康檢查，你應該使用else if，在這種情況下else是不夠的：

   #include <iostream> 
   using namespace std; 
   int main() 
   { 
       int num1 , num2; 
   
       cout<< " Enter number 1 and number 2 \n"; 
       cin>> num1 >> num2; 
   
       if (num1 == num2) 
        cout<< "The both numbers are equal \n"; 
       else if (num1> num2) 
        cout<< "Number 1 is greater than number 2 \n"; 
       else if (num1< num2) 
        cout<< "Number 2 is greater than number 1 \n"; 
       return 0; 
   } 
   

Answer 3

; is not placed after `if` condition 

此外，否則不會得到一個條件...它總是檢查它的相應if的否定。 事實上如果if條件不爲else塊保存代碼被執行....改變

else (num1< num2) 
     cout<< "Number 2 is greater than number 1 \n"; 

到

else 
     cout<< "Number 2 is greater than number 1 \n"; 

您的問題將得到解決。