std::string explanation; // this upper coding
char explanation; //after entering void to display
You need to decide if explanation should be defined as std::string or char. char only stores one character (you need char explanation or some other int if you want to use an array of char), so given that you want to use the
syntax I suspect it should be defined as the first. Your error is probably something along the lines of "explanation: already defined", which you get because you've defined it twice.
In future, if you get errors, tell us what they are. It's not always this easy to guess what those errors might be.