Write a function that finds the first element that appers an even number of times in an unsorted array.

find element that appers even number of times.

Write a function that finds the first element that appers an even number of  times in an unsorted array.
// input: [5,3,5,1,5,1,3]
// output: 3

let arr = [5,3,5,1,5,1,3];
let value = '';
for(let i = 0; i < arr.length; i++){
  let val = arr[i];
  if(arr.filter((v) => v === val).length % 2 == 0){
    value = val;
  }
};