有代码不懂，望大佬进来看看！ - 编程论坛

#include <iostream>
using namespace std;

int main()
{
    const int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31};
    int index;

    for (index = 0; index < sizeof days / sizeof days[0]; index++)
        cout << "Month " << index + 1 << " has " << days[index] << " days.\n";
    cout << endl;
    return 0;
}

这一段不懂

for (index = 0; index < sizeof days / sizeof days[0]; index++)

有大神可以解释一下吗？？

然后输出为什么是

Month 1 has 31 days.
Month 2 has 28 days.
Month 3 has 31 days.
Month 4 has 30 days.
Month 5 has 31 days.
Month 6 has 30 days.
Month 7 has 31 days.
Month 8 has 31 days.
Month 9 has 30 days.
Month 10 has 31 days.

谢谢大神指导！！