C++ Check that in a string only exist following characters - c++

Question

The valid charaters are
// ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_/
#include <iostream>
#include <string>
using namespace std;
int main();
{
bool bIsValid = true;
// test characters
string strCheck("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_/");
string s("foo#?+baa") ; // should bring a "false" because of the "#?+" characters
string::const_iterator it = strCheck.begin();
// this is NOT a clever soulution has anybody a better idea ?
while (s.find(*it) != string::npos)
{
++it;
if(!s.find((*it))
{
bIsValidKey = false;
break;
}
}
cout << "Is Valid: " << bIsValid << endl ;
}
My problem is how can a get the first charater after the iteratorpoint to compare
with the allowed charactes. I need something like (*it).first_charater_after to
solve the problem.
Dos anybody has an other idea to check that in the string only exists a defined
number of charaters?

Answer 1

Use string::find_first_not_of?

Answer 2

Try this:
#include <iostream>
#include <string>
#include <regex>
using namespace std;
int main()
{
bool bIsValid = true;
string s("GHHbaa111__") ; // Add/remove other characters
regex r("^[[:alnum:]_]*$");
if (regex_match(s,r)) {
cout << "Valid string" << endl;
} else {
cout << "Invalid string" << endl;
}
}

Answer 3

#include <iostream>
#include <string>
int main() {
bool bIsValid = true;
// test characters
std::string strCheck("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_/");
std::string s("foo#?+baa") ; // should bring a "false" because of the "#?+" characters
if (s.find_first_not_of(strCheck) != std::string::npos)
bIsValid = false;
std::cout << "Is Valid: " << bIsValid << std::endl ;
}