string c 2b 2b if letter is lowercase

1for(int i=0;i<str.size();i++){
2int c = str[i]; 
3        if (islower(c))  
4            str[i] = toupper(c);
5}

1if (isupper(str[i])) {
2	// str[i] is uppercase
3}

1str[i] = toupper(str[i]);

1char test='a';
2cout<<isalpha(test);