循环读取dat文件错误

Question

Goodday，

我有一个读取dat文件的循环，但循环读取的数据不正确。我的dat文件包含以下数据

46780976 3750.40
W 250.00
D 1200.00
W 75.00
W 375.00
D 1200.00
I 5.50
W 400.00
W 600.00
D 450.50
W 35.65

输出应为

Account number: 46780976
Opening balance: R3750.40

Transaction    Amount    Balance Bank costs
Withdrawal     250.00    4000.00
Deposit       1200.00Ct  2800.00
Withdrawal        75.00  2725.00
Withdrawal      1375.00   1350.00
Deposit        1200.00Ct 1550.00
Interest         5.50    1555.50
Withdrawal      400.00   1155.50
Withdrawal      600.00   555.50     25.00
Deposit         450.00Ct 1005.50
Withdrawal       35.65    969.85
Banking costs    25.00    969.60

Closing balance: R969.60

我得到以下

Account number : 46780976

Opening Balance : R 3750.4

Transaction        Amount          Balance         Bank Costs


Withdrawal            250            3500.4
Deposit            0 Ct            3500.4
Interest              0            3500.4

Withdrawal            250            3225.4
Deposit            1200 Ct            4425.4
Interest              0            4425.4

Withdrawal            75            4325.4
Deposit            1200 Ct            5525.4
Interest              0            5525.4

Withdrawal            375            5125.4
Deposit            1200 Ct            6325.4
Interest              0            6325.4

Withdrawal            375            5925.4
Deposit            1200 Ct            7125.4
Interest              0            7125.4

Withdrawal            375            6725.4
Deposit            1200 Ct            7925.4
Interest              5.5            7930.9

Withdrawal            400            7505.9
Deposit            1200 Ct            8705.9
Interest              5.5            8711.4

Withdrawal            600            8086.4
Deposit            1200 Ct            9286.4
Interest              5.5            9291.9

Withdrawal            600            8666.9
Deposit            450.5 Ct            9117.4
Interest              5.5            9122.9

Withdrawal            35.65            9062.25
Deposit            450.5 Ct            9512.75
Interest              5.5            9518.25

Withdrawal            35.65            9457.6
Deposit            450.5 Ct            9908.1
Interest              5.5            9913.6
Bank Costs           25            9888.6            25


Closing Balance : R 9888.6
Press any key to continue . . .

我的代码：

do { 
   in_stream >> letter;

if (letter == 'W')

    in_stream >> withdrawal;
    openBalance -= withdrawal;
    cout << "\nWithdrawal" << "            "<< withdrawal << "            " << openBalance << endl;
    out_stream << withdrawal;

if (letter == 'D')

    in_stream >> deposit;
    openBalance += deposit;
    cout << "Deposit" <<"            "<< deposit <<" Ct" <<"            " << openBalance << endl;
    out_stream << deposit;


if (letter == 'I')

    in_stream >> interest;
    openBalance += interest;
    cout << "Interest" <<"              "<< interest <<"            " << openBalance << endl;
    out_stream << interest;

 if (openBalance < 1000)
     cout << "Bank Costs" <<"           "<< bankCost <<"            " << openBalance <<"            " << bankCost << endl;
    openBalance -= bankCost;
    out_stream << bankCost;

} while(!in_stream.eof());

请指出正确的方向

感谢

Answer 1

你的第一个问题是你的if块。在C ++中，'if'语句会影响以下内容：代码行或block.so ...

if( Xxx )
    thisHappensOnlyIfXxxIsTrue
thisAlwaysHappens

if( Xxx )
    thisHappensOnlyIfXxxIsTrue
    thisAlwaysHappens  // even though it's indented


if( Xxx ) {
    thisHappensOnlyIfXxxIsTrue
    thisDependsOnXxxToo
}
thisAlwaysHappens

下一个问题是，每次循环重启时都不会清除变量。你需要插入一个

do {
   deposit = 0;
   interest = 0;
   withdrawal = 0;

在循环的开头（或结束），以确保您不会重复使用上次循环迭代中的值。

Answer 2

第一行是：

46780976 3750.40

此行将通过，但没有预期的内容：

in_stream >> letter;

当然假设letter的类型为char

修改

// You need to read in the initial values here

do { 
   in_stream >> letter;

if (letter == 'W')
{
    in_stream >> withdrawal;
    openBalance -= withdrawal;
    cout << "\nWithdrawal" << "            "<< withdrawal << "            " << openBalance << endl;
    out_stream << withdrawal;
}

if (letter == 'D')
{
    in_stream >> deposit;
    openBalance += deposit;
    cout << "Deposit" <<"            "<< deposit <<" Ct" <<"            " << openBalance << endl;
    out_stream << deposit;
}

if (letter == 'I')
{

    in_stream >> interest;
    openBalance += interest;
    cout << "Interest" <<"              "<< interest <<"            " << openBalance << endl;
    out_stream << interest;
 }

 if (openBalance < 1000)
 {
     cout << "Bank Costs" <<"           "<< bankCost <<"            " << openBalance <<"            " << bankCost << endl;
    openBalance -= bankCost;
    out_stream << bankCost;
  }

} while(!in_stream.eof());