getline不要求输入？

Question

这可能是一个非常简单的问题，但请原谅我，因为我是新人。这是我的代码：#include <iostream>#include <string>#include <sstream>using namespace std;int main (){    string name;   int i;   string mystr;   float price = 0;   cout << "Hello World!" << endl;   cout << "What is your name? ";   cin >> name;   cout << "Hello " << name << endl;   cout << "How old are you? ";   cin >> i;   cout << "Wow " << i << endl;   cout << "How much is that jacket? ";   getline (cin,mystr);   stringstream(mystr) >> price;   cout << price << endl;   system("pause");   return 0;}问题是当被问及how much is that jacket?getline没有要求用户输入时，只输入初始值“0”。为什么是这样？