A Very Big Sum

Calculate and print the sum of the elements in an array, keeping in mind that some of those integers may be quite large.

Function Description:

Complete the aVeryBigSum function in the editor below. It must return the sum of all array elements.

aVeryBigSum has the following parameter(s):

ar: an array of integers.

Input Format:

The first line of the input consists of an integer.
The next line contains space-separated integers contained in the array.

Output Format:

Print the integer sum of the elements in the array.

My Solution:

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
inputString += inputStdin;
});

process.stdin.on('end', _ => {
inputString = inputString.replace(/\s*$/, '')
.split('\n')
.map(str => str.replace(/\s*$/, ''));

main();
});

function readLine() {
return inputString[currentLine++];
}

function aVeryBigSum(ar) {
var sum=0;
for(let i=0;i<ar.length;i++){
sum = sum + ar[i];
}
return sum;
}

function main() {
const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

const arCount = parseInt(readLine(), 10);

const ar = readLine().split(' ').map(arTemp => parseInt(arTemp, 10));

let result = aVeryBigSum(ar);

ws.write(result + "\n");

ws.end();

}