Yes, and no... What you have is an array.
food[0] = "Burger";
food[1] = "Fries";
food[2] = "Pasta";
Then you have 3 integer variables set to a value
int Burger=100;
int Fries =200;
int Pasta=300;
Now you can add Burger + Fries to get a value of 300...
A string hold characters....
string Burger ="1";
string Fries="2";
string Pasta="3";
They have no numeric value. You can't add Burger and Fries to get 3 this way. You may convert the string to an integer. or use Enum, but a string holding an integer is not allowed in c++ to the best of my knowledge.