# Subarrays product sum in JavaScript

JavascriptWeb DevelopmentFront End TechnologyObject Oriented Programming

We are required to write a JavaScript function that takes in an array of numbers of length N such that N is a positive even integer and divides the array into two sub arrays (say, left and right) containing N/2 elements each.

The function should do the product of the subarrays and then add both the results thus obtained.

For example, If the input array is −

const arr = [1, 2, 3, 4, 5, 6]

Then the output should be −

(1*2*3) + (4*5*6)
6+120
126

The code for this will be −

const arr = [1, 2, 3, 4, 5, 6]
const subArrayProduct = arr => {
const { length: l } = arr;
const creds = arr.reduce((acc, val, ind) => {
let { left, right } = acc;
if(ind < l/2){
left *= val;
}else{
right *= val;
}
return { left, right };
}, {
left: 1,
right: 1
});
return creds.left + creds.right;
};
console.log(subArrayProduct(arr));

Following is the output on console −

126
Published on 09-Oct-2020 11:36:15