Give a definition for the function with the following function declaration. The class BankAccount is defined in Display 10.5. double difference(BankAccount account1, BankAccount account2);...

Give a definition for the function with the following function declaration.

The class BankAccount is defined in Display 10.5.

double difference(BankAccount account1, BankAccount account2);

//Precondition: account1 and account2 have been given values

//(that is, their member variables have been given values).

//Returns the balance in account1 minus the balance in

account2.