The following methods can be used to manipulate the output.
| setw ( int ) | width of the next field | <iostream> |
|
|
|
| setprecision (int) | precision for the next fixed
decimal number | <iomanip> |
|
|
|
| setbase (int) | number base for the next
integer number | <iomanip> |
|
|
|
| setfill ( char ) | filling for space unused by
the next field | <iomanip> |
#include<ostream.h>
#include<iomanip.h>
using namespace std;
int main() {
cout << 123.456789 << endl
<< setw(9) << 123.456789 << endl
<< setw(12) << 123.456789 << endl;
cout << setprecision (1) << 123.456789 << endl
<< setprecision (3) << 123.456789 << endl
<< setprecision (8) << 123.456789 << endl
<< setprecision (9) << 123.456789 << endl;
cout << setbase( 8 ) << 100 << endl
<< setbase( 16 ) << 100 << endl ;
cout << setfill( '.' ) << setw(10) << 123 << endl;
return 0;
}
-_-_-
123.457
123.457
123.457
1e+02
123
123.45679
123.456789
144
64
........7b
The following methods of <iostream> can be used to manipulate flags that
control the I/O format.
| fmtflags setf | ( fmtflags fmtfl ) | set the flags specified in the
argument |
|
|
|
| fmtflags unsetf | ( fmtflags fmtfl ) | clear the flags specified in
the argument |
|
|
|
| fmtflags setf | ( fmtflags fmtfl,
fmtflags mask ) | set the flags that are
common to fmtfl and mask
clear the flags referenced in
fmtfl but not in mask |
|
|
|
setiosflags
resetiosflags | ( fmtflags fmtfl ) | flag for next fieldd |
The following flags are offered by <iomanip.h>
| ios::skipws | skip whitespace in input |
#include <iostream>
#include<iomanip.h>
using namespace std;
int main() {
char c;
cin.unsetf( ios::skipws );
while ( cin >> c ){
cout << c;
}
cout << endl;
return 0;
}
-_-_-
Five words
in two lines.
ios::left
ios::right | justified output |
#include <iostream>
#include<iomanip.h>
using namespace std;
int main() {
cout.setf ( ios_base::left );
cout << setw(10) << 123 << endl;
cout.setf ( ios_base::right );
cout << setw(10) << 123 << endl;
return 0;
}
-_-_-
123
123
| ios::basefield | (de) activate |
|
|
ios::dec
ios::oct
ios::hex | number system |
|
|
| ios::uppercase | for letters in hexadecimal
numbers |
|
|
| ios::basefield | ios_base::hex |
ios_base::oct |
ios_base::dec |
#include <iostream>
using namespace std;
int main () {
cout.setf ( ios_base::hex, ios_base::basefield );
cout.setf ( ios_base::showbase );
cout << 100 << endl;
cout.unsetf ( ios_base::showbase );
cout << 100 << endl;
return 0;
}
-_-_-
0x64
64