c++ - 只返回 x=a 或 'start' 变量的第一个值

Question

#include <iostream>
using namespace std;
int sumTo(int a, int b);


int main()
{
int start;
int end;

cout << "Enter one number " << endl;
cin >> start;
cout << "The second number  " << endl;
cin >> end;

int total = sumTo(start, end);


cout << "The sum of the integers btween these 2 numbers is " <<total<<endl ;

return 0;

}
int sumTo(int a, int b)
{
    int sum = 0;
    for (int x = a; x <= b; x++)
    {

        sum += x;
        cout << sum << endl;
        return sum;
    }
}

你好，这个需要找到两个输入数字之间所有数字的总和。现在它只返回第一个输入数字不知道为什么？

Answer 1

您的代码的问题在于 return sum; 已置于 for 循环内。这将导致 for 循环只运行一次，因为该函数已经返回了 sum 的值，即 a。

int sumTo(int a, int b)
{
    int sum = 0;
    for (int x = a; x <= b; x++)
    {

        sum += x;
        cout << sum << endl;
        return sum; // Here is your problem.
    }
}

你的函数其实应该是

int sumTo(int a, int b)
{
    int sum = 0;
    for (int x = a; x <= b; x++)
    {

        sum += x;
        cout << sum << endl;
    }
        return sum; // This line should be placed here instead.
}