1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
// Fig. 14.8: fig14_08.cpp
// Credit inquiry program.
#include <iostream>
using std::cout;
using std::cin;
using std::ios;
using std::cerr;
using std::endl;
using std::fixed;
using std::showpoint;
using std::left;
using std::right;
#include <fstream>
using std::ifstream;
#include <iomanip>
using std::setw;
using std::setprecision;
#include <cstdlib>
enum RequestType { ZERO_BALANCE = 1, CREDIT_BALANCE,
DEBIT_BALANCE, END };
int getRequest();
bool shouldDisplay( int, double );
void outputLine( int, const char * const, double );
int main()
{
// ifstream constructor opens the file
ifstream inClientFile( "clients.dat", ios::in );
// exit program if ifstream could not open file
if ( !inClientFile ) {
cerr << "File could not be opened" << endl;
exit( 1 );
} // end if
int request;
int account;
char name[ 30 ];
double balance;
// get user's request (e.g., zero, credit or debit balance)
request = getRequest();
// process user's request
while ( request != END ) {
switch ( request ) {
case ZERO_BALANCE:
cout << "\nAccounts with zero balances:\n";
break;
case CREDIT_BALANCE:
cout << "\nAccounts with credit balances:\n";
break;
case DEBIT_BALANCE:
cout << "\nAccounts with debit balances:\n";
break;
} // end switch
// read account, name and balance from file
inClientFile >> account >> name >> balance;
// display file contents (until eof)
while ( !inClientFile.eof() ) {
// display record
if ( shouldDisplay( request, balance ) )
outputLine( account, name, balance );
// read account, name and balance from file
inClientFile >> account >> name >> balance;
} // end inner while
inClientFile.clear(); // reset eof for next input
inClientFile.seekg( 0 ); // move to beginning of file
request = getRequest(); // get additional request from user
} // end outer while
cout << "End of run." << endl;
return 0; // ifstream destructor closes the file
} // end main
// obtain request from user
int getRequest()
{
int request;
// display request options
cout << "Enter request" << endl
<< " 1 - List accounts with zero balances" << endl
<< " 2 - List accounts with credit balances" << endl
<< " 3 - List accounts with debit balances" << endl
<< " 4 - End of run" << fixed << showpoint;
// input user request
do {
cout << "\n? ";
cin >> request;
} while( request < ZERO_BALANCE && request > END );
return request;
} // end function getRequest
// determine whether to display given record
bool shouldDisplay( int type, double balance )
{
// determine whether to display credit balances
if ( type == CREDIT_BALANCE && balance < 0 )
return true;
// determine whether to display debit balances
if ( type == DEBIT_BALANCE && balance > 0 )
return true;
// determine whether to display zero balances
if ( type == ZERO_BALANCE && balance == 0 )
return true;
return false;
} // end function shouldDisplay
// display single record from file
void outputLine( int account, const char * const name,
double balance )
{
cout << left << setw( 10 ) << account << setw( 13 ) << name
<< setw( 7 ) << setprecision( 2 ) << right << balance
<< endl;
} // end function outputLine
/**************************************************************************
* (C) Copyright 1992-2003 by Deitel & Associates, Inc. and Prentice *
* Hall. All Rights Reserved. *
* *
* DISCLAIMER: The authors and publisher of this book have used their *
* best efforts in preparing the book. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
* no warranty of any kind, expressed or implied, with regard to these *
* programs or to the documentation contained in these books. The authors *
* and publisher shall not be liable in any event for incidental or *
* consequential damages in connection with, or arising out of, the *
* furnishing, performance, or use of these programs. *
*************************************************************************/
|
