Question

寻找有关如何在for语句中计算用户输入数字总和并在for循环完成后打印它的一些见解。

到目前为止，我有这段代码：

//this code will sort 2 numbers then print them in ascending order and 
before exiting, add them all together 
// then average them

#include <iostream>
using namespace std;

int main(int,char**) {

int n, m, z, sort1, sort2;

for (n=0;n<3;n++){
  cout << " enter two integers (n n): ";
  cin >> m;
  cin >> z;

    if (m>z){
        sort1 = z;
        sort2 = m;
    }
    else{
        sort1 = m;
        sort2 = z;
    }
     cout << sort1 << sort2 << endl;
  }
int sum = m+z;
int sum2 = m+z+sum;
float sum3= m+z+sum2;
cout << " sum of all numbers entered: " << sum << endl;
cout << " average of the numberes entered: " << sum3 /6 << endl;
}

所以我知道我的sum函数是不正确的，它只评估用户输入的最后一个m + z而不是其他的。如果我将sum函数放在循环中，一旦它中断，它就会转储循环中的所有信息，使得sum值过时。想知道是否有另一种方法可以在循环中实现sum函数，但只能在循环外打印一次。

是否有其他循环不会删除循环中可以从外部提取的信息？

Answer 1

C ++中的所有循环都是作用域的，这意味着在作用域内声明的任何变量都不能在作用域之外访问，也不会持续到下一次迭代。

int sum = 0; // declare sum outside of loop
for(int n = 0; 0 < 3; n++)
{
   int m, z; // These will be reset every iteration of the for loop
   cout << " enter two integers (n n): ";
   cin >> m;
   cin >> z;

   /*
       Sort and print goes here...
   */

   sum += m + z;
}
std::cout << "The sum: " << sum <<std::endl;

Answer 2

#include<iostream>
using namespace std;

int main()
{

    int total = 0, i, j, sort1, sort2;

    //this For-Loop will loop three times, every time getting two new 
    //integer from the user

    for (int c = 0; c < 3; c++) {
        cout << "Enter two integers ( n n ): ";
        cin >> i;
        cin >> j;

   //This will compare if first number is bigger than the second one. If it 
   //is, then second number is the smallest
        if (i > j) {
            sort1 = j;
            sort2 = i;
        }
        else {
            sort1 = i;
            sort2 = j;
        }

        cout << "The numbers are: " << sort1 << " and " << sort2 << endl;

   //This statement will add into the variable total, the sum of both numbers entered before doing another loop around
        total += i + j;
    }

    cout << "The sum of all integers entered is: " << total << endl;

    system("pause");

    return 0;
}

for循环中的SUM函数，C ++

2 个答案: