Usage of setiosflags () in C + +

Cout<<setiosflags (ios::fixed) <<setiosflags (ios::right) <<setprecision (2);

Setiosflags is a C + + operator that is contained in the namespace Iomanip, which is the function of executing a parameter specified by the

Action within the area;

Iso::fixed is one of the parameters of the operator setiosflags, which specifies that the action is to represent a floating point in the form of a decimal point

To the right of the decimal point as far as possible within the allowable accuracy range;

Iso::right is also a setiosflags parameter that specifies the right-aligned output within the specified area.

Setprecision is also a C + + operator contained in the namespace Iomanip, which functions as a set of floating-point numbers;

Setprecision (2) means the precision of the decimal point output, that is, the number of digits to the right of the decimal point is 2.

Cout<<setiosflags (ios::fixed) <<setiosflags (ios::right) <<setprecision (2);

Together, the output is a floating-point number with a right-aligned two-digit decimal point.

Use Setprecision (n) to control the number of floating-point numbers displayed by the output stream. The default stream output value for C + + is 6.

If Setprecision (n) is combined with setiosflags (ios::fixed), you can control the number of digits to the right of the decimal point.

Setiosflags (ios::fixed) is a fixed-point representation of real numbers

Add:

Q: What is the role of COUT.SETF () and Cout.precision () in C + +?

For:

These two are the ~ostream member functions of the format control, you can also use the output stream operator to control, all the same ~ attached to you some look ~

Which COUT.SETF and setiosflags the same, cout.precision and setprecision like ~

#include <iomanip>

The Iomanip is more useful in this:

Mainly for cin,cout, such as some manipulation operators, such as setfill,setw,setbase,setprecision and so on. This is the I/O flow control header

Like the formatted output in C. Here are some common control functions:

Dec base is 10 equivalent to "%d"

Hex base is 16 equivalent to "%x"

The OCT has a base of 8 equivalent to "%o"

Setfill (c) Set the fill character to C

Setprecision (n) Set display decimal precision is n bit

SETW (n) Set a field width of n characters

This control means that the output width is guaranteed to be N. Such as:

COUT<<SETW (3) <<1<<SETW (3) <<10<<SETW (3) <<100; The output result is

1 10100 (the default is right-aligned) when the output length is greater than 3 o'clock (<<1000), SETW (3) does not work.

Setioflags (ios::fixed) fixed floating-point display

Setioflags (ios::scientific) index indicates

Setiosflags (ios::left) Align Left

Setiosflags (ios::right) Align Right

Setiosflags (IOS::SKIPWS ignores leading whitespace

Setiosflags (ios::uppercase) 16 Decimal Capital Output

Setiosflags (ios::lowercase) 16 binary lowercase output

Setiosflags (ios::showpoint) force display decimal point

Setiosflags (ios::showpos) force display symbols

Example:

#include <iostream>

#include <iomanip>

using namespace Std;

int main ()

{

cout<<12345.0<<endl;//Output "12345"

Cout<<setiosflags (ios::fixed) <<setprecision (3) <<1.2345<<endl; output "1.235"

Cout<<setiosflags (ios::scientific) <<12345.0<<endl;//output "1.234500e+

004 "

Cout<<setprecision (3) <<12345.0<<endl;//output "1.235e+004"

return 0;

}

Usage of setiosflags () in C + +