Check if the input is a number or string in C++

Question

I wrote the following code to check whether the input(answer3) is a number or string, if it is not a number it should return \"Enter Numbers Only\" but it returns the same e

Answer 1

The function isdigit() is used to test for only digits ( 0,1,...,9)

use this function to check for numbers

bool is_number(const std::string& s)
{
    std::string::const_iterator it = s.begin();
    while (it != s.end() && std::isdigit(*it)) ++it;
    return !s.empty() && it == s.end();
}