table of contents
std::setbase(3) | C++ Standard Libary | std::setbase(3) |
NAME¶
std::setbase - std::setbase
Synopsis¶
Defined in header <iomanip>
/*unspecified*/ setbase( int base );
Sets the numeric base of the stream. When used in an expression out <<
setbase(base)
or in >> setbase(base), changes the basefield flag of the stream out or
in,
depending on the value of base:
* the value 16 sets basefield to std::ios_base::hex
* the value 8 sets std::ios_base::oct
* the value 10 sets std::ios_base::dec.
Values of base other than 8, 10, or 16 reset basefield to zero, which
corresponds to
decimal output and prefix-dependent input.
Parameters¶
base - new value for basefield
Return value¶
Returns an object of unspecified type such that if str is the
name of an output
stream of type std::basic_ostream<CharT, Traits> or
std::basic_istream<CharT,
Traits>, then the expression str << setbase(base) or str >>
setbase(base) behaves as
if the following code was executed:
str.setf(base == 8 ? std::ios_base::oct :
base == 10 ? std::ios_base::dec :
base == 16 ? std::ios_base::hex :
std::ios_base::fmtflags(0),
std::ios_base::basefield);
Example¶
// Run this code
#include <iostream>
#include <sstream>
#include <iomanip>
int main()
{
std::cout << "Parsing string \"10 0x10
010\"\n";
int n1, n2, n3;
std::istringstream s("10 0x10 010");
s >> std::setbase(16) >> n1 >> n2 >> n3;
std::cout << "hexadecimal parse: " << n1 << ' '
<< n2 << ' ' << n3 << '\n';
s.clear();
s.seekg(0);
s >> std::setbase(0) >> n1 >> n2 >> n3;
std::cout << "prefix-dependent parse: " << n1 <<
' ' << n2 << ' ' << n3 << '\n';
std::cout << "hex output: " << std::setbase(16)
<< std::showbase << n1 << ' ' << n2 << ' '
<< n3 << '\n';
}
Output:¶
Parsing string "10 0x10 010"
hexadecimal parse: 16 16 16
prefix-dependent parse: 10 16 8
hex output: 0xa 0x10 0x8
See also¶
dec changes the base used for integer I/O
hex (function)
oct
showbase controls whether prefix is used to indicate numeric base
noshowbase (function)
2022.07.31 | http://cppreference.com |