main 函数

#include <iostream>

using namespace std;

//int main(int argc, char **argv) // 命令行选项，前边是个数，后边是字符转数组，每一个选项是一个字符串，
//{
//	cout << argv[0] << endl; // argv[0]不是命令行选项，
//	cout << argv[1] << endl;
//	cout << argv[2] << endl;
//	for (int i = 0; i < argc; ++i)
//		cout << "循环：" << argv[i] << endl;
//	int start, end, step;
//	start = atoi(argv[1]);
//	end = atoi(argv[2]);
//	step = atoi(argv[3]);
//	for (int k = start; k <= end; k += step)
//		cout << k << endl;
//	return 0;
//}

int main(int argc, char* argv[])
{
if (argc != 3)
{
cout << "you should use three arguments!" << endl;
return -1;
}
cout << "这两个数的和是：" << (atof(argv[1]) + atof(argv[2])) << endl;
}