我希望让用户输入一个数字作为字符串,将其转换为浮点数,测试它是否成功,如果输入为’Q’则退出或打印“无效输入”如果它不是’Q’uit字符和返回更多输入.@H_403_3@

转换失败测试的语法是什么？它会是ss.fail()吗？@H_403_3@

// using stringstream constructors.
#include <iostream>
#include <sstream>
using namespace std;

int main () {

  int val;
  stringstream ss (stringstream::in | stringstream::out);

  ss << "120 42 377 6 5 2000";

  /* Would I insert an 

     if(ss.fail())
       { 
        // Deal with conversion error }
       }

    in here?! */


  for (int n=0; n<6; n++)
  {
    ss >> val;
    cout << val*2 << endl;
  }

  return 0;
}