Equal Sides Of An Array.js

// You are going to be given an array of integers.
//  Your job is to take that array and find an index N where the sum of the integers to the left of N is equal to the sum of the integers to the right of N. If there is no index that would make this happen, return -1.

// For example:

// Let's say you are given the array {1,2,3,4,3,2,1}:
// Your function will return the index 3, because at 
// the 3rd position of the array, the sum of left side of the index ({1,2,3}) and the sum of the right side of the index ({3,2,1}) both equal 6.

// Let's look at another one.
// You are given the array {1,100,50,-51,1,1}:
// Your function will return the index 1, because at the 1st position of the array, the sum of left side of the index ({1}) and the sum of the right side of the index ({50,-51,1,1}) both equal 1.

// Last one:
// You are given the array {20,10,-80,10,10,15,35}
// At index 0 the left side is {}
// The right side is {10,-80,10,10,15,35}
// They both are equal to 0 when added. (Empty arrays are equal to 0 in this problem)
// Index 0 is the place where the left side and right side are equal.

// Note: Please remember that in most programming/scripting languages the index of an array starts at 0.

// Input:
// An integer array of length 0 < arr < 1000. The numbers in the array can be any integer positive or negative.

// Output:
// The lowest index N where the side to the left of N is equal to the side to the right of N. If you do not find an index that fits these rules, then you will return -1.

// Note:
// If you are given an array with multiple answers, return the lowest correct index.

function findEvenIndex(arr){
    //Code goes here!
    for (let i = 0; i < arr.length; i++) {
          const leftSum = arr.slice(0, i).reduce((acc, val) => acc + val, 0);
          const rightSum = arr.slice(i + 1).reduce((acc, val) => acc + val, 0);
          if (leftSum === rightSum) {
              return i;
          }
      }
      return -1;
  }