C++ <valarray> - operator- Function

The C++ <valarray> operator- function is used to apply minus operator to each element of two valarrays, or a valarray and a value.

Syntax

template <class T>
  valarray<T> operator- 
    (const valarray<T>& lhs, const valarray<T>& rhs);
template <class T>
  valarray<T> operator- 
    (const T& val, const valarray<T>& rhs);
template <class T>
  valarray<T> operator- 
    (const valarray<T>& lhs, const T& val);

Parameters

`lhs`	Specify left-hand side valarray.
`rhs`	Specify right-hand side valarray.
`val`	Specify a value of type T.

Return Value

Returns a new valarray object containing elements as a result of performing operation on each element.

Time Complexity

Depends on library implementation.

Example:

The example below shows the usage of operator- function.

#include <iostream>
#include <valarray>
using namespace std;
 
int main (){
  valarray<int> va1 {10, 20, 30, 40};
  valarray<int> va2 {5, 10, 15, 20};
  valarray<int> va3, va4;

  //result of va1 - 3 is stored in va3 
  va3 = va1 - 3;

  cout<<"va3 contains: ";
  for(int i = 0; i < va3.size(); i++)
    cout<<va3[i]<<" ";

  //result of va1 - va2 is stored in va4 
  va4 = va1 - va2;

  cout<<"\nva4 contains: ";
  for(int i = 0; i < va4.size(); i++)
    cout<<va4[i]<<" ";  
    
  return 0;
}

The output of the above code will be:

va3 contains: 7 17 27 37 
va4 contains: 5 10 15 20

❮ C++ <valarray> Library