共用方式為


valarray::operator-

A unary operator that applies a minus to each element in a valarray.

valarray<Type> operator-( ) const;

Return Value

A valarray whose elements are minus those of the operand array.

Example

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

int main( )
{
   using namespace std;
   int i;

   valarray<int> vaL ( 10 );
   valarray<int> vaMINUS ( 10 );
   for ( i = 0 ; i < 10 ; i += 2 )
      vaL [ i ] =  -i;
   for ( i = 1 ; i < 10 ; i += 2 )
      vaL [ i ] =  i-1;
   
   cout << "The initial valarray is:  ( ";
      for ( i = 0 ; i < 10 ; i++ )
         cout << vaL [ i ] << " ";
   cout << ")." << endl;

   vaMINUS = -vaL;
   cout << "The element-by-element result of "
        << "the operator+ is the\n valarray: ( ";
      for ( i = 0 ; i < 10 ; i++ )
         cout << vaMINUS [ i ] << " ";
   cout << ")." << endl;
}
The initial valarray is:  ( 0 0 -2 2 -4 4 -6 6 -8 8 ).
The element-by-element result of the operator+ is the
 valarray: ( 0 0 2 -2 4 -4 6 -6 8 -8 ).

Requirements

Header: <valarray>

Namespace: std

See Also

Reference

valarray Class