Question

In C++ design a function that determines if an email entered by a user is from an approved email extension. It will return true if the email is valid and false if it is not. The function must also throw an exception if "@" is not in the string argument.

Function Prototype:

bool validEmail(string);

Approved Email Extensions:

list <string> validEmailExtensions = { "@aol.com", "@yahoo.com", "@icloud.com", "@hotmail.com"};

Answer 1

Here is the completed code for this method. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. If not, PLEASE let me know before you rate, I’ll help you fix whatever issues. Thanks

//required method

bool validEmail(string email){

                //creating a list of valid extensions

                list <string> validEmailExtensions = { "@aol.com", "@yahoo.com", "@icloud.com", "@hotmail.com"};

                //if @ is not found, throwing an exception with a string message.

                if(email.find("@")==string::npos){

                                throw "@ is not found!";

                }

                //looping through the validEmailExtensions list using an iterator

                for(list<string>::iterator it=validEmailExtensions.begin();it!=validEmailExtensions.end();it++){

                                //fetching current value

                                string ext=*it;

                                //making sure that email's length is greater than extension's length

                                if(email.length()>ext.length()){

                                                //checking if email ends with current extension (not just contains, we are checking that

                                                //the last ext.length() characters in email is equal to the string ext or not.)

                                                if(email.compare(email.length()-ext.length(),ext.length(),ext)==0){

                                                                return true; //valid

                                                }

                                }

                               

                }

                //no extensions match, invalid.

                return false;

}