Question

我一直在研究一个读取不同货币文件的数据结构程序，然后我将其用于转换。我已经连续几天跑了过来，并尝试了fgets，fscanfs等等，而我现在只是因为我对编程很陌生而迷失了。

数据。文件在如下的单独行中列出：

dollar 1.00

yen 0.0078

franc 0.20

mark 0.68

pound 1.96

到目前为止我的代码：

  typedef struct {
   string currency;
   double rate;
   } currencyT;

  typedef struct {
   currencyT cur[MaxCurrencyTypes];
   int nCurrency;
   } *currencyDB;


  static currencyDB ReadDataBase(void);  
  static ReadOneLine(FILE *infile, currencyDB db);  

  static currencyDB ReadDataBase(void)
 {
   FILE *infile;
   currencyDB db;
      int nCurrency;

   db = New(currencyDB);
   infile = fopen(ExchangeFile, "r");
       while (ReadOneLine(infile, db));
   fclose(infile);
   return(db);
 }

  static ReadOneLine(FILE *infile, currencyDB db) 
 {
   currencyT cur;
   char termch, currency;
   double rate;
   int nscan, nCurrency;


   nCurrency = 0;

   while(1) {
       nscan = fscanf(infile, "%20s %f%c", db->cur[nCurrency].currency, 
  &db->cur[nCurrency].rate, &termch);
           if(nscan = EOF) break;
           if(nscan != 3 || termch != '\n') {
               Error("Improper file format");
               }
           nCurrency++;
           }
       db->nCurrency = nCurrency;  
   }


 static void ProcessExchange(currencyDB db)
 {

 }



 main()
 {
   currencyDB currencies;

   currencies = ReadDataBase();

   ProcessExchange(currencies);


 }

Answer 1

见8＆amp;首先是9。

MaxCurrencyTypes未声明，我们假设
```
#define MaxCurrencyTypes (5)
```
string未声明，我们假设
```
typedef char * string;
```

currencyDB是指针类型，建议改为声明为结构类型

typedef struct {
  currencyT cur[MaxCurrencyTypes];
  int nCurrency;
} currencyDB;  // Drop *

static ReadOneLine()应使用显式返回类型。
```
static int ReadOneLine()
```
int nCurrency;未在ReadDataBase()中使用。

New()中db = New(currencyDB)未声明或定义。假设为*db分配未初始化的内存。

ExchangeFile未声明。
if (nscan = EOF) - ＆gt; if (nscan == EOF)
ReadOneLine()需要返回一个值。
main()应明确说明返回类型和参数。
```
int main(void)  
```

货币转换数据库结构来自文本文件

1 个答案: