valarray::sum

Determines the sum of all the elements in a valarray of nonzero length.

Type sum( ) const;

Return Value

The sum of the elements of the operand valarray.

Remarks

If the length is greater than one, the member function adds values to the sum by applying operator+= between pairs of elements of class Type, which operator, consequently, needs be provided for elements of type Type.

Example

// valarray_sum.cpp
// compile with: /EHsc
#include <valarray>
#include <iostream>

int main( )
{
   using namespace std;
   int i;
   int sumva = 0;

   valarray<int> va ( 10 );
   for ( i = 0 ; i < 10 ; i+=1 )
      va [ i ] =  i;

   cout << "The operand valarray va (10) is: ( ";
      for ( i = 0 ; i < 10 ; i++ )
         cout << va [ i ] << " ";
   cout << ")." << endl;

   sumva = va.sum ( );
   cout << "The sum of elements in the valarray is: "
        << sumva  << "." <<endl;
}

The operand valarray va (10) is: ( 0 1 2 3 4 5 6 7 8 9 ).
The sum of elements in the valarray is: 45.

Requirements

Header: <valarray>

Namespace: std

See Also

Concepts

valarray Class

valarray Members