15.string

#include<iostream>
#include <string>
#include <typeinfo>
using std::string;
using std::cout;
using std::cin;
using std::endl;

int main()
{
    string str{"hello world!!!"};
    int count = 0;
    for ( decltype(str.size()) index = 0; index!=str.size() && !isspace(str[index]); ++index)
    {
        str[index] = toupper(str[index]);
    }
    cout << str << endl;
    system("pause");
    return 0;
}