std::fixed, std::scientific, std::hexfloat, std::defaultfloat
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Déclaré dans l'en-tête <ios> | ||
std::ios_base& fixed(std::ios_base& str ); | (1) | |
std::ios_base& scientific(std::ios_base& str ); | (2) | |
std::ios_base& hexfloat(std::ios_base& str ); | (3) | (depuis C++11) |
std::ios_base& defaultfloat(std::ios_base& str ); | (4) | (depuis C++11) |
Modifie le formatage par défaut en virgule flottante I / O
1) Original:
Modifies the default formatting for floating-point I/O
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définit le
2) floatfield
de la str
flux de fixed
comme si en appelant str.setf(std::ios_base::fixed, std::ios_base::floatfield)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.
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définit le
3) floatfield
de la str
flux de scientific
comme si en appelant str.setf(std::ios_base::scientific, std::ios_base::floatfield)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.
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définit le
4) basefield
du flux str
à fixed
et scientific
simultanément, comme si en appelant str.setf(std::ios_base::fixed|std::ios_base::scientific, std::ios_base::floatfield). Cela permet hexadécimal à virgule flottante en forme .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.
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définit le
basefield
de la str
flux à zéro, comme si en appelant str.unsetf(std::ios_base::floatfield). Ceci permet à la virgule flottante par défaut de mise en forme, qui est différente de fixe et scientifique .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.
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Il s'agit d'un manipulateur d'E / S, il peut être appelé avec une expression telle que pour tout out << std::fixed
out
de std::basic_ostream type ou d'une expression telle que pour tout in >> std::scientificin
de std::basic_istream type .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.
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Sommaire |
[modifier]Paramètres
str | - | référence aux flux d'entrée / sortie 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. |
[modifier]Retourne la valeur
str
(référence au flux après la manipulation)Original:
str
(reference to the stream after manipulation)The text has been machine-translated via Google Translate.
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[modifier]Exemple
#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';}
Résultat :
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
[modifier]Voir aussi
changements à virgule flottante de précision Original: changes floating-point precision The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction) |