ios_base& boolalpha ( ios_base& str );

<ios>

Alphanumerical bool values

Sets the boolalpha format flag for the str stream.

When the boolalpha format flag is set, bool values are insterted/extracted as their names: true and false instead of integral values.

This flag can be unset with the noboolalpha manipulator.

The boolalpha flag is not set in standard streams on initialization.

Parameters

str

Stream object where to apply.
Because this function is a manipulator, it is designed to be used alone with no arguments in conjunction with the insertion (<<) and extraction (>>) operations on streams (see example below).

Return Value

Example

// modify boolalpha flag
#include <iostream>
using namespace std;

int main () {
  bool b;
  b=true;
  cout << boolalpha << b << endl;
  cout << noboolalpha << b << endl;
  return 0;
}

The execution of this example displays something similar to:

true
1

See also