c++ - How to make cin take only numbers -

here code

double enter_number() {   double number;   while(1)   {          cin>>number;         if(cin.fail())         {             cin.clear();             cin.ignore(numeric_limits<streamsize>::max(), '\n');             cout << "invalid input " << endl;         }         else         break;         cout<<"try again"<<endl;   }   return number; } 

my problem when enter 1x, 1 taken input without noticing character left out run. there way how make work real number e.g. 1.8?

i use std::getline , std::string read whole line , break out of loop when can convert entire line double.

#include <string> #include <sstream>  int main() {     std::string line;     double d;     while (std::getline(std::cin, line))     {         std::stringstream ss(line);         if (ss >> d)         {             if (ss.eof())             {   // success                 break;             }         }         std::cout << "error!" << std::endl;     }     std::cout << "finally: " << d << std::endl; }