在循环中使用stringstream从几个字符串中提取数字(Using stringstream inside a loop to extract a number from few strings)

 我目前正在练习使用stringstreams从字符串中提取值。 在这个简单的代码中，用户输入一个名称和一个数字（用空格分隔），这个字符串存储在“input”中。 然后，它传递给“流”并分隔名称和数字，它们存储在“名称”和“数字”中。 然后，使用std :: cout输出数字。 此过程使用不同的名称和数字完成几次。 
 
#include <sstream>
#include <iostream>

int main() {
    std::string input;
    std::stringstream stream;
    std::string name;
    double amount;

    for (;;) {
        std::getline(std::cin, input);      // enter a name, a whitespace and a number
        stream.str(input);
        stream >> name >> amount;           // problem here
        std::cout << amount << std::endl;

    }
    return 0;
}
 
 问题：只有第一个输入的输入数存储在“金额”中。 下一个输入的数量不会存储在“金额”中（金额内部始终具有相同的数字）。 也许，我不知道有什么关于stringstreams ... 

I'm currently practicing with stringstreams to extract values from a string. In this simple code, user enters a name and a number (separated by a space), this string is stored in "input". Then, it's passed to "stream" and it separates the name and the number, which are stored in "name" and "number". Then, the number is output with std::cout. This process is done a few times with different names and numbers.
 
#include <sstream>
#include <iostream>

int main() {
    std::string input;
    std::stringstream stream;
    std::string name;
    double amount;

    for (;;) {
        std::getline(std::cin, input);      // enter a name, a whitespace and a number
        stream.str(input);
        stream >> name >> amount;           // problem here
        std::cout << amount << std::endl;

    }
    return 0;
}
 
Problem: Only the number of the first entered input is stored in "amount". The numbers of the next inputs will not be stored in "amount" (amount always has the same number inside). Maybe, there is something I don't know about stringstreams...

原文：https://stackoverflow.com/questions/50780656