C++ <valarray> - operator*= Function

The C++ valarray::operator*= function is used to apply compound assignment operator (multiply 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 multiply and assignment operation on each element of the given valarray.

#include <iostream>
#include <valarray>
using namespace std;
 
int main (){
  valarray<double> varr1 {10, 20, 30, 40};
  valarray<double> varr2 {4, 3, 2, 1};

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

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

  //further multiplying each elements 
  //of varr1 by 0.5
  varr1 *= 0.5;

  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: 40 60 60 40 
varr1 contains: 20 30 30 20

❮ C++ <valarray> Library