Joining Strings or characters

[project science]

Hi!

I'm trying to join two letters together into 1 string. Basically, I'm trying to mock up a table in which a user puts in their full name and phone number. Where I am running into trouble is I can get the first letter of the persons first and last name, but I cannot seem to combine these 2 letters together into 1 string.

I'd like to have it to the effect on line 52:
string initials = "first" + "last";

Not sure what I'm doing wrong.

or maybe from line 36,37, it should look similar to:

string initials = char first = name_full.at(0) + char last = name_full.at(name_full.find(" ",0) + 1)

Any ideas?

/*
User will enter their name and their phone number into program and have the program then strip out the name, 
placing it into a column in a table, and then stripping the phone number from format: xxx-xxx-xxxx, and putting 
area code in column 2, and rest of phone number in column 3  (Perhaps even add a memo  to each number, such as mobile or home?, or stripping initial from first / last name
*/

#include <iostream>
#include <string>

using namespace std;

int main()
{
// table: 5x4 (rowsxcolumns)  Columns: 1. Full Name, 2. Initials, 3. Area Code (000), 4. Phone Number (000-0000)
string table[5][4];

// variables of contacts
string name_first;
string name_last;
string phone_number;
string name_full;

// enter their first & last names - make this a function?
cout << "Enter a name (first space last): ";
getline(cin,name_full);

// enter phone number
cout << "Enter a phone number, in the format: 000-000-0000: ";
getline(cin,phone_number);

// display text
cout << "\nFull name: " << name_full << endl;
cout << "Phone number: " << phone_number << endl;

// get characters in string
char first = name_full.at(0);
char last = name_full.at(name_full.find(" ",0) + 1);
/* This finds the character " " between the first and last names, and then
gets the character +1 after this position.  It utilitzes a function within another
*/
cout << "\nFirst letter in the FIRST name: " << first << endl;
cout << "\First letter of the LAST name: " << last << endl; 

// place name into table
table[0][0] = name_full;  

// place initials into table
  //name_full.insert(name_full.at(name_full.find(" ",0) + 1));
   //name_full.insert(6,first);

// char combine = last(first);
string initials = "first" + "last";

table[0][1] = initials;  

// display table
cout << "\nTable data which has been entered" << endl;	
cout << table[0][0] << " " << table [0][1] << endl;    

cin.get();
cin.ignore();
return 0;
}

[mobotus]

string initials;
initials = first + last;

[project science]

I did something sorta of similar which works by converting 1 char character into a string:

string initials = string(1,first) + string(1,last);