How to check std::string if its indeed an integer?

Question

The following code converts an std::string to int and the problem lies with the fact that it cannot discern from a true integer or just a random st

Answer 1

You may try to use Boost lexical_cast, it will throw an exception if the cast failed.

int number;
try
{
     number = boost::lexical_cast(str);
}
catch(boost::bad_lexical_cast& e)
{
    std::cout << str << "isn't an integer number" << std::endl;
}

EDIT Accorinding to @chris, You may also try to use std::stoi since C++11. It will throw std::invalid_argument exception if no conversion could be performed. You may find more information here: std::stoi