function quickCheck(arr, elem) {
  // change code below this line
  
  for(var i=0; i<arr.length; i++) {
    var posicion = arr.indexOf(arr[i])
    if(posicion)
  }
  // change code above this line
}

// change code here to test different cases:
console.log(quickCheck(['squash', 'onions', 'shallots'], 'mushrooms'));