請問為什麼下列程式所建立的txt檔內容是錯誤的 AnsiString str; FILE *fp; str="123.txt"; fp=fopen(str.c_str(),"w"); long double a=0.0005456444444444887; fprintf(fp,"%f\n",a);

請問為什麼下列程式所建立的txt檔內容是錯誤的 AnsiString str; FILE *fp; str="123.txt"; fp=fopen(str.c_str(),"w"); long double a=0.0005456444444444887; fprintf(fp,"%f\n",a); fclose(fp);

These modifiers determine how printf functions interpret the next input argument, arg[f].    Prefix        Format specifier        Type specified
F        p s                   A far pointer
N        n                  A near pointer
h        d i o u x X        A short int
l        d i o u x X        A long int
l        e E f g G                 A double
L        e E f g G                 A long double
L        d i o u x X        An __int64
h        c C        A single-byte character
l        c C        A Wide character
h        s S        A single-byte character string
l        s S        A Wide character string
These modifiers affect how all the printf functions interpret the
 data type of the corresponding input argument arg.    Both F and N reinterpret the input variable arg. Normally, the arg 
for a %p, %s, or %n conversion is a pointer of the default size for
 the memory model.    h, l, and L override the default size of the numeric data input 
arguments. Neither h nor l affects pointer (p,n) types.
 

這是BCB online的說明，另外 你的資料超出有效範圍了，會有部份資料無法存入， 可能要找個大一點的格式， 照上面的說明，可以試試: fprintf(fp,"%Lf\n",a); 或 fprintf(fp,"%Le\n",a); 這個會比較好 國泰平安 發表人 -

非常感謝..您是我的救命恩人阿..