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 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)
{
  if (arr.length === 0){
    return 0;
  } else{
      for(let i = 0; i < arr.length; i++){
        let sum1 = arr.slice(0, i).reduce((a,b)=>a+b,0);
        let sum2 = arr.slice(i+1, arr.length).reduce((a,b)=>a+b,0);
        if (sum1 === sum2){
          return i
        }
  }
    return -1
  }

}