t

t.js

function findShortestWordAmongMixedElements(listOfWords) {
  var data = listOfWords;
  var result;
  var not_a_string = data.length;

  if (data.length == 0) {
    return '';
  }

  for(i=0;i<data.length;i++) {
    if (typeof data[i] === 'string') {
      if(typeof result === 'undefined') {
        result = data[i];
      }

      if(data[i].length < result.length) {
        result = data[i];
      }
    } else {
      not_a_string--;
    }
  }

  if(!not_a_string) {
    result = '';
  }

  return result;
}

findShortestWordAmongMixedElements([4,2,3,1]);