// update balance in record
void updateRecord( fstream &updateFile )
{
// obtain number of account to update
int accountNumber = getAccount( "Enter account to update" );
// move file-position pointer to correct record in file
updateFile.seekg( ( accountNumber - 1 ) * sizeof( ClientData ) );
// read first record from file
ClientData client;
updateFile.read( reinterpret_cast< char * >( &client ),
sizeof( ClientData ) );
// update record
if ( client.getAccountNumber() != 0 )
{
outputLine( cout, client ); // display the record
// request user to specify transaction
cout << "\nEnter charge (+) or payment (-): ";
double transaction; // charge or payment
cin >> transaction;
// update record balance
double oldBalance = client.getBalance();
client.setBalance( oldBalance + transaction );
outputLine( cout, client ); // display the record
// move file-position pointer to correct record in file
updateFile.seekp( ( accountNumber - 1 ) * sizeof( ClientData ) );
// write updated record over old record in file
updateFile.write( reinterpret_cast< const char * >( &client ),
sizeof( ClientData ) );
} // end if
// display single record
void outputLine( ostream &output, const ClientData &record )
{
output << left << setw( 10 ) << record.getAccountNumber()
<< setw( 16 ) << record.getLastName()
<< setw( 11 ) << record.getFirstName()
<< setw( 10 ) << setprecision( 2 ) << right << fixed
<< showpoint << record.getBalance() << endl;
} // end function outputLine
