Ayxan Haqverdili
2020-11-28 17:28:51
Read an entire line at once as a string and validate:
#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cctype>
int main()
{
std::printf("Enter x: ");
std::string line;
while (true)
{
if (!std::getline(std::cin, line))
{
std::puts("Stream failed."); // Not much we can do
return -1;
}
if (std::all_of(line.cbegin(), line.cend(), std::isdigit))
break;
else
std::printf("Input is not a number. Try again: ");
}
int const x = std::stoi(line);
std::printf("x = %d\n", x);
}