名前空間
変種
操作

std::fixed, std::scientific, std::hexfloat, std::defaultfloat

提供: cppreference.com
< cpp‎ | io‎ | manip

 
 
 
入出力マニピュレータ
浮動小数点フォーマット
fixedscientifichexfloatdefaultfloat
(C++11)(C++11)
整数フォーマット
ブーリアンフォーマット
フィールド幅とフィル制御
その他のフォーマット
ホワイトスペース処理
出力のフラッシュ
ステータスフラグ操作
時間と通貨の入出力
(C++11)
(C++11)
(C++11)
(C++11)
引用符マニピュレータ
(C++14)
 
ヘッダ <ios> で定義
(1)
std::ios_base& scientific( std::ios_base& str );
(2)
std::ios_base& hexfloat( std::ios_base& str );
(3) (C++11およびそれ以降)
std::ios_base& defaultfloat( std::ios_base& str );
(4) (C++11およびそれ以降)
浮動小数点のI / O用の既定の書式を変更します
Original:
Modifies the default formatting for floating-point I/O
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
1)
ストリームのfloatfieldを設定strfixedかのようにstr.setf(std::ios_base::fixed, std::ios_base::floatfield)を呼び出すことによって
Original:
sets the floatfield of the stream str to fixed as if by calling str.setf(std::ios_base::fixed, std::ios_base::floatfield)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
2)
ストリームのfloatfieldを設定strscientificかのようにstr.setf(std::ios_base::scientific, std::ios_base::floatfield)を呼び出すことによって
Original:
sets the floatfield of the stream str to scientific as if by calling str.setf(std::ios_base::scientific, std::ios_base::floatfield)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
3)
ストリームのbasefieldを設定strfixedscientific同時にstr.setf(std::ios_base::fixed | std::ios_base::scientific, std::ios_base::floatfield)を呼び出したかのように。これは、16進数浮動小数点フォーマットを可能に.
Original:
sets the basefield of the stream str to fixed and scientific simultaneously as if by calling str.setf(std::ios_base::fixed | std::ios_base::scientific, std::ios_base::floatfield). This enables hexadecimal floating-point formatting.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
4)
basefieldを呼び出したかのように、ゼロにストリームstrstr.unsetf(std::ios_base::floatfield)を設定します。これは、固定および科学とは異なるデフォルトの浮動小数点フォーマットを可能に.
Original:
sets the basefield of the stream str to zero, as if by calling str.unsetf(std::ios_base::floatfield). This enables the default floating-point formatting, which is different from fixed and scientific.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
これは、I / Oのマニピュレータである、そのようなタイプのout << std::fixedのいずれout、またはそのようなタイプの任意のstd::basic_ostreamin >> std::scientificためinとして式を持つstd::basic_istreamとして式と呼ばれるかもしれない.
Original:
This is an I/O manipulator, it may be called with an expression such as out << std::fixed for any out of type std::basic_ostream or with an expression such as in >> std::scientific for any in of type std::basic_istream.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

目次

[編集] パラメータ

str -
I / Oストリームを参照します
Original:
reference to I/O stream
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] 値を返します

str(操作後のストリームへの参照)
Original:
str (reference to the stream after manipulation)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集]

#include <iostream>
#include <sstream>
int main()
{
    std::cout << "The number 0.01 in fixed:      " << std::fixed << 0.01 << '\n'
              << "The number 0.01 in scientific: " << std::scientific << 0.01 << '\n'
              << "The number 0.01 in hexfloat:   " << std::hexfloat << 0.01 << '\n'
              << "The number 0.01 in default:    " << std::defaultfloat << 0.01 << '\n';
    double f;
    std::istringstream("0x1P-1022") >> std::hexfloat >> f;
    std::cout << "Parsing 0x1P-1022 as hex gives " << f << '\n';
}

出力:

The number 0.01 in fixed:      0.010000
The number 0.01 in scientific: 1.000000e-02
The number 0.01 in hexfloat:   0x1.47ae147ae147bp-7
The number 0.01 in default:    0.01
Parsing 0x1P-1022 as hex gives 2.22507e-308

[編集] 参照

浮動小数点の精度を変更します
(関数) [edit]