奇怪的十六進制答案簡單的數學代碼::塊

Question

我想在C++書中做下列任務。

運行此之後：

#include <iostream> 

using namespace std; 

int main() 
{ 
double first_arg; 
double second_arg; 

cout << "Enter first argument: "; 
cin >> first_arg; 
cout << "Enter second argument: "; 
cin >> second_arg; 

cout << first_arg << " * " << second_arg << " = " 
    << cout << first_arg * second_arg << "\n"; 

cout << first_arg << " + " << second_arg << " = " 
    << cout << first_arg + second_arg << "\n"; 

cout << first_arg << "/" << second_arg << " = " 
    << cout << first_arg/second_arg << "\n"; 

cout << first_arg << " - " << second_arg << " = " 
    << cout << first_arg - second_arg << "\n"; 

我得到一些意想不到的結果。這樣的結果直接從Windows的命令行復制：

Enter first argument: 7 
Enter second argument: 9 
7 * 9 = 0x6fcc43c463 
7 + 9 = 0x6fcc43c416 
7/9 = 0x6fcc43c40 
7 - 9 = 0x6fcc43c4-2 

我使用的是最新版本的默認編譯器設置代碼塊的。謝謝。

Answer 1

cout << first_arg << " * " << second_arg << " = " 
    << cout << first_arg * second_arg << "\n"; 

你有兩種cout一條線，因爲沒有上線別無分號1

爲了解決這個問題無論是擺脫第二cout或在第一行的每個COUT末尾加上一個分號聲明。

如果你看看每個答案的最後2位數字，你會看到你想要得到的答案，所以它仍然打印出你想要的答案，只是指針指向cout。