C++ Standard Library C++ STL Library

C++ <valarray> - operator- Function

The C++ valarray::operator- function is used to apply unary minus operator to each element of the valarray.


valarray<T> operator-() const;


No parameter is required.

Return Value

Returns a new valarray object with modified values.

Time Complexity

Depends on library implementation.


In the example below, the valarray::operator- function is used to perform unary minus operation on each element of the given valarray.

#include <iostream>
#include <valarray>
using namespace std;
int main (){
  valarray<int> varr1 {10, 20, 30, 40};
  //result of unary minus operation 
  //on varr1 is stored in varr2
  valarray<int> varr2 = -varr1;

  cout<<"varr1 contains: ";
  for(int i = 0; i < varr1.size(); i++)
    cout<<varr1[i]<<" ";

  cout<<"\nvarr2 contains: ";
  for(int i = 0; i < varr2.size(); i++)
    cout<<varr2[i]<<" ";   
  return 0;

The output of the above code will be:

varr1 contains: 10 20 30 40 
varr2 contains: -10 -20 -30 -40 

❮ C++ <valarray> Library