std::setw
From cppreference.com
| Defined in header <iomanip>
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| /*unspecified*/ setw( int n ); |
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When used in an expression out << setw(n) or in >> setw(n), sets the width parameter of the stream out or in to exactly n. This value is not "sticky": the next input or output operation that is affected by the value of the stream's width field, resets it to zero (meaning "unspecified").
Contents |
[edit] Parameters
| n | - | new value for width |
[edit] 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 << setw(n) or str >> setw(n) behaves as if the following code was executed:
str.width(n);
[edit] Example
#include <sstream> #include <iostream> #include <iomanip> int main() { std::cout << "no setw: " << 42 << '\n' << "setw(6): " << std::setw(6) << 42 << '\n'; std::istringstream is("hello, world"); char arr[10]; is >> std::setw(6) >> arr; std::cout << "Input from \"" << is.str() << "\" with setw(6) gave \"" << arr << "\"\n"; }
Output:
no setw: 42 setw(6): 42 Input from "hello, world" with setw(6) gave "hello"
[edit] See also
| manages field width (public member function of std::ios_base) | |
| changes the fill character (function template) | |
