first.js

function firstNotRepeatedChar(str) {
  var arr = str.split('');
  var result = '';
  var count = 0;

  for (var i = 0; i < arr.length; i++) {
    count = 0;

    for (var y = 0; y < arr.length; y++) {
      if (arr[i] == arr[y]) {
        count +=1;
      }
    }

    if (count < 2) {
      result = arr[i];
      break;
    }
  }

  return result;
}