Question

我看到很多关于将for循环转换为while和while循环的问题，但是我似乎无法在转换while循环时找到任何东西在C ++中执行while循环。它仍然需要保持与原始代码相同的功能。

以下是原始代码：

int number, product = 1, count = 0; 

cout << "Enter a whole number to be included in the product" 
<< endl << "or enter 0 to end the input: "; 
cin >> number; 

while (number != 0) 
{
product = product * number; 
count++; 
cout << "Enter a whole number to be included in the product" 
<< endl << "or enter 0 to end the input: "; 
cin >> number; 
} 

if (count > 0) 
{ 
cout << endl << "The product is " << product << "." << endl; 
}

通过移动它，我能够在这里结束，但我总是以错误结束。当我运行程序时，它会提示我输入一个while数字，就像预期的那样。如果我输入一个有效的数字，它会循环并询问我同样的问题。然后，当我输入0时，它会像往常一样踢出，但无论之前输入的数字是什么，它都显示产品为0。

这是我尝试将其调整为do while循环：

int main()
{   

int number, product = 1, count = 0; 

do
{
    cout << "Enter a whole number to be included in the product" << endl << "or enter 0 to end the input: "; 
    cin >> number; 
    product = product * number; 
    count++; 
}

while (number != 0);
{
    if (count > 0) 
    cout << endl << "The product is " << product << "." << endl; 
}
}

Answer 1

在插入0时的do .. while循环中，首先将乘积乘以0，而不是存在。因此产品始终为0。

之前移动产品：

int count = -1, number = 1, product = 1; 
do
{
    count++;
    product = product * number; // you can use product *= number;
    cout << "Enter a whole number to be included in the product" << endl << "or enter 0 to end the input: "; 
    cin >> number;
}    
while (number != 0);

if (count > 0) 
    cout << endl << "The product is " << product << "." << endl;

注意：我的代码不使用其他if，但仍保留相同的功能。

Answer 2

测试号码！= 0，然后再分配产品=产品* nuumber

否则，当用户输入0时，乘以0并退出循环

Answer 3

问题是在do-while版本中，当用户输入0这一行时：

product = product * number;

已执行，而while版本未执行。

因此，产品将始终为0。

如果数字为0，则不要乘以product。

Answer 4

您的问题是退出时number输入为0，这使您的整个产品等于0.尝试此逻辑：

#include <iostream>

int main() {

    int number = 0, product = 1, count = 0;

    do {
        std::cout << "Enter a whole number to be included in the product" << std::endl << "or enter 0 to end the input: ";
        std::cin >> number;
        if (number > 0) {
            product = product * number;
            count++;
        }
    } while (number != 0);
    {
        if (count > 0)
            std::cout << std::endl << "The product is " << product << "." << std::endl;
    }
}

Answer 5

如果你只是想解决问题，你得到0作为你的答案，那么问题是由于以下几行

cin >> number; 
product = product * number;

你取0的数字并乘以产品，结果显然是0。

你可以通过发表一个中断声明来修复它。

cin >> number;
if(number == 0)
break;
product = product * number;

但是，总的来说，我不确定你是通过尝试解决这个问题来实现的，即将一段时间转换为一段时间。

Answer 6

int number, product = 1, count = 0; 

cout << "Enter a whole number to be included in the product" 
     << endl << "or enter 0 to end the input: "; 
cin >> number; // you enter a non-0 number here

while (number != 0) // you now loop until you hit 0 ...
{
    product = product * number; 
    count++; 
    cout << "Enter a whole number to be included in the product" 
         << endl << "or enter 0 to end the input: "; 
    cin >> number; // you overwrite the non-0 number you had previously input
} 

if (count > 0) 
{ 
    cout << endl << "The product is " << product << "." << endl; 
}

在不知道程序的完整上下文的情况下，我猜这里，但您可以将其重写为：

int number = 0, product = 1, count = 0; 

do
{
    cout << "Enter a whole number to be included in the product" 
         << endl << "or enter 0 to end the input: ";
    cin >> number;
    if (number != 0)
    {
        count++;
        product *= number;
    } 
} while (number != 0); // exit the loop when you have a non-zero entry

if (count > 0) 
{ 
    cout << endl << "The product is " << product << "." << endl; 
}

或......

int number = 0, product = 1; 

do
{
    cout << "Enter a whole number to be included in the product" 
         << endl << "or enter 0 to end the input: ";
    cin >> number;
    if (number != 0)
    {
        product *= number;
    } 
} while (number != 0); // exit the loop when you have a non-zero entry

cout << endl << "The product is " << product << "." << endl;

您可以避免第二个条件，因为您从潜在输入中排除0，并且只是始终输出产品。

Answer 7

无论您获得什么输入，都会增加count。首先检查输入是否为零（您的中止输入）。

更改

count++

到

if (number)
    count++;

C ++将while循环转换为do-while循环

7 个答案: