. , . , , :
ifstream() ofstream() fstream()
{ { {
} } }
, . , ifstream ifs; ofstream ofs; fstream f1,f2;
, . :
ifstream(const char*name,int omode=ios::in,int prot=filebuf::openprot);
ofstream(const char*name,int omode=ios::out,int prot=filebuf::openprot);
fstream (const char*name,int omode, int prot=filebuf::openprot);
24. 3
, ifstream, ofstream fstream. . ifstream ofstream . . fstream : .
.
ifstream ifs1(ish.dan);
ofstream of1(rezult.dan);
ofstream of2(rezult2.txt,ios::app);
rezult2.txt (append).
fstream fil1(file1.txt,ios::in);
file1.txt .
fstream fil2(file2.dan,ios::out);
fstream fil3(file3.dan,ios::app);
file2.dan file3.dan .
open() ios. :
filebuf*open(const char*name,int mode, int prot=filebuf::openprot);
: (). ios.
num open_mode
{
in=0x01://open for reading
out=0x02://open for writing
ate=0x04://seek to end of file upon original//open
app=0x08://append mode
trunc=0x10://trancate file if already exist
nocreate=0x20:// open fails if file doesnt exist
noreplace=0x40:// open fails if file already exists
binary=0x80:// binary file
};
.
, :
fstream fin, fout;
fin.open(ish.dan, ios::in);
fout.open(rez.dan, ios::out);
. . :
fout.open(rez.dan, ios::out|ios::ate);
close, . :
fin.close ();
fout.close ();
, ( ) .
.
1 . ish.dan, rez.dan.
|
|
|
# include < iostream. h >
# include < fstream. h >
# include < math. h >
# include < stdlib. h >
void main ()
{
ifstream fin (ist. dan);
if (fin)
{
cout << ish. dan <<\ n ;
exit (1);
}
ofstream fout (rez. dan);
double x, y, xn, dx, xk;
fin >>xn>>dx>>xk;
fout << xn= <<xn<< dx= <<dx<< xk = <<xk<< \ n ;
for (x = xn; x <= xk; x += dx)
{
y = exp (-x);
fout << x = <<x<< y = << y << \ n;
}
fin. close ();
fout. close ();
}
2 .
. - , - . .
# include < iostream. h >
# include < fstream. h >
# include < stdlib. h >
# define N 2
# define M 3
class matr
{
float x [ N ] [ M ];
public:
void vvod (char * S);
void vivod (char * S);
friend matr operator + (matr & a, matr & b);
};
void matr:: vvod (char * S)
{
ifstream ifs (S);
if (ifs)
{
cout << << S << \ n ;
exit (1);
}
for (int i = Ø; i < N; i + +)
for (int j = Ø; j < M; j + +)
ifs >> x [ i ][ j ];
}
void matr:: vivod (char * S)
{
ofstream ofs (S);
for (int i = Ø; i < N; i ++)
for (int j = Ø; j < M; j ++)
ofs <<x [ i ][ j ];
}
matr operator + (matr & a, matr & b)
{
matr z;
for (int i = Ø; i < N; i ++)
for (int j = Ø; j < M; j ++)
z. x [ i ] [ j ] = a. x [ i ] [ j ] = b. x [ i ] [ j ];
return z;
}
void main ()
{
matr v, w, q
v. vvod (v. dan);
w. vvod (w. dan);
q = v + w;
q. vivod (q. dan);
}
v w v.dan w.dan. q q.dan.
24.5 /
, . :
friend ifstream & operator >> (ifstream & ifs, & );
friend ofstream & operator << (ofstream & ofs, & );
. , , v hod. dan.
v [ 2 ] [ 3 ] w [ 2 ] [ 3 ]. v hod. dan. , v hod. dan :
1 2 3
4 5 6
-1 -2 -3
-4 -5 -6
v, w.
# include < iostream. h >
# include < fstream. h >
# include < stdlib.h >
# define N 2
# define M 3
class matr
{
float x [ N ] [ M ];
friend ifstream & operator >> (ifstream & ifs, matr & x);
friend ofstream & operator << (ofstream & ofs, matr & a);
friend matr operator + (matr & a, matr & b);
|
|
|
};
ifstream & operator >> (instream & ifs, matr & x)
{
for (int I = Ø; I < N; I ++)
for (int j = Ø; j < M; j ++)
ifs >>x. x [ I ] [ j ]; / * * /.
return ifs; // !
}
ofstream & operator << (ofstream & ofs, matr & a)
{
for (int I = Ø; I < N; I ++)
for (int j = Ø; j < M; j ++)
ofs << a. x [ I ] [ j ];
return ofs;
}
matr operator + (matr & a, matr & b)
{
matr v;
for (int I = Ø; I < N; I ++)
for (int j = Ø; j < M; j ++)
v. x [ I ] [ j ] = a. x [ I ] [ j ] + b. x [ I ] [ j ];
return v;
}
void main ()
{
matr w, v;
ifstream fvh (v hod. dan);
fvh >> v >> w; // * >>. v, w */
matr q;
q = v + w; // + ().
ofstream viv (q. dan);
viv << q; // q q.dan.
// << ().
}
25
+ + : , .
