input: from typing import List
  
  
  def linearSearch(search_item: str) -> int:
      """ Perform a linear search through the predefined array to find the position of the search item.
      If the item is found, return its position; otherwise, return -1.
      >>> linearSearch('school')
      0
      >>> linearSearch('mall')
      3
      >>> linearSearch('park')
      -1
      """
output:     predefined_array = ['school', 'library', 'gym', 'mall', 'hospital']
      for i in range(len(predefined_array)):
          if predefined_array[i] == search_item:
              return i
      return -1