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C++ : Reference : STL Containers : bitset : count
 
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bitset::count

public member function 
size_t count ( );

Count bits set

Returns the amount of bits in the bitset that are set (i.e., have a value of 1).

Parameters

none

Return value

The number of bits set.

size_t is an unsigned integral type.

Example

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// bitset::count
#include <iostream>
#include <string>
#include <bitset>
using namespace std;

int main ()
{
  bitset<8> myset (string("10110011"));

  cout << "myset has " << int(myset.count()) << " ones ";
  cout << "and " << int(myset.size()-myset.count()) << " zeros.\n";

  return 0;
}


Output:
myset has 5 ones and 3 zeros.

See also

bitset::size Return size (public member function)
bitset::any Test if any bit is set (public member function)
bitset::none Test if no bit is set (public member function)