if in an array of integers, every number comes in even times whereas only one number appears odd times code example

Example: Given an array of integers, find the one that appears an odd number of times. There will always be only one integer that appears an odd number of times

function findOdd(A) {
    var countOccurencesOfInt = 0;
    for (let i = 0; i < A.length; i++) {
        var currentIterationInt = A[i];
        for (let j = 0; j < A.length; j++) {
            if (currentIterationInt == A[j]) {
                countOccurencesOfInt++;
            }
        }
        if (countOccurencesOfInt % 2 != 0) {
            return currentIterationInt;
        }
    }
}
//or
function findOdd(arr) {
  var result, num = 0;

  arr = arr.sort();
  for (var i = 0; i < arr.length; i++) {
    if (arr[i] === arr[i+1]) {
      num++;
    } else {
      num++;
      if (num % 2 != 0) {
        result = arr[i];
        break;
      }
    }
  }
  return result;
}