C++ <valarray> - operator-= Function

The C++ valarray::operator-= function is used to apply compound assignment operator (minus AND assignment operator) to each element of the valarray.

Syntax

valarray<T>& operator-=( const valarray<T>& v );
valarray<T>& operator-=( const T& val );

Parameters

`v`	Specify another valarray.
`val`	Specify a value of type T.

Return Value

Returns the left hand side valarray object.

Time Complexity

Depends on library implementation.

Example:

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

#include <iostream>
#include <valarray>
using namespace std;
 
int main (){
  valarray<int> varr1 {10, 20, 30, 40};
  valarray<int> varr2 {5, 6, 7, 8};

  //result of varr1 - varr2 stored in varr1 
  varr1 -= varr2;

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

  //further subtracting 100 to each 
  //elements of varr1
  varr1 -= 100;

  cout<<"\nvarr1 contains: ";
  for(int i = 0; i < varr1.size(); i++)
    cout<<varr1[i]<<" "; 
    
  return 0;
}

The output of the above code will be:

varr1 contains: 5 14 23 32 
varr1 contains: -95 -86 -77 -68

❮ C++ <valarray> Library