input: from typing import List
  
  def linearSearch(search_item: str, array: List[str]) -> int:
      """
      Perform a linear search through a given array to find the index of a search item.
      If the search item is not found, return -1.
  
      >>> linearSearch('hospital', ['school', 'hospital', 'bookstore', 'mall', 'theatre'])
      1
      >>> linearSearch('library', ['school', 'hospital', 'bookstore', 'mall', 'theatre'])
      -1
      """
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1
output:     for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1