不懂 while 循环语法

Question

我需要有关输入驱动循环的帮助，这意味着用户输入两个值并打印和、差、乘积、商和余数，直到用户为第二个值输入零。我不明白如何编写 while 循环我正在测试什么变量

这是一个示例：

enter two integers: 19 7
sum of 19 and 7 is 26
difference of 19 and 7 is 12 
etc..

Answer 1

我假设您是初学者...并且您正在使用 <iostream>。如果您正在使用其他东西，例如<cstdio> 然后评论，我会更改代码，但它是这样的：（对于乘法，你可以算出其余的：D）

#include <iostream>
using namespace std;
int main (){
    int num1;
    int num2;
    while (true){
         cout << "Enter some numbers";
         cin >> num1 >> num2;
         cout << "Product is " << num1*num2;
    }
    return 0;
}

祝你编码顺利！

Answer 2

你可以尝试这样的事情。使用无限循环并根据自己的情况打破循环。

#include <iostream>
using namespace std;
int main (){
    int num1, num2;
    while (1){
         cout << "\nEnter some numbers ";
         cin >> num1 >> num2;
         if(num2==0)
               break;
         cout << "Product is " << num1*num2;
    }
    return 0;
}

Answer 3

使用带有 break 条件的无限循环就可以了。这是

#include<iostream>
int main()
  {
    int a , b;
    while( 1 )
      {
        std :: cout << "\nEnter two integers :" ;
        std :: cin >> a >> b ;
        if ( b == 0 )
           break;
        std :: cout << "\nSum of " << a << " and " << b << " is " << a + b ;
        std :: cout << "\nDifference of " << a << " and " << b << " is " << a - b ;
        std :: cout << "\nProduct of " << a << " and " << b << " is " << a * b ;
        std :: cout << "\nQuotient when " << a << " is divided by " << b << " is " << a / b ;
        std :: cout << "\nRemainder when " << a << " is divided by " << b << " is " << a % b ;
      }
    return 0;
  }

如果 b == 0，您只需使用 break。当遇到break时，程序退出循环。（如果你是个菜鸟，不知道如何使用 break，请阅读这篇 break ）

while( 1 )是死循环，只有遇到break程序才会退出循环

另请记住，% 不适用于浮点数。如果你想要浮动，那么你将不得不使用 std::fmod() ( std :: fmod( a , b ); returns a 除以 b 的余数，其中 a和 b 是浮点数或双精度数，它包含在 <cmath> 头文件中）。

Answer 4

这可以通过多种方式完成。例如

while ( true )
{
   std::cout << "Enter two integer numbers: ";

   int first;
   int second = 0;

   std::cin >> first >> second;

   if ( second == 0 ) break;

   std::cout << "sum of " << first 
                << " and " << second 
                << " is " << first + second;
                << std::endl;

   std::cout << "difference of " << first 
                << " and " << second 
                << " is " << first - second;
                << std::endl;

   // and other outputs if they are required
}

不懂 while 循环语法

Dont understand while loop syntax

c++

loops

while-loop