input: from typing import List
  
  def linearSearch(search_item: str, array: List[str]) -> int:
      """Implements a simple linear search algorithm to find the index of the search_item in the given array.
      If the item is not found, returns -1.
      >>> linearSearch('bookstore', ['school', 'hospital', 'bookstore', 'mall', 'theatre'])
      2
      >>> linearSearch('park', ['school', 'hospital', 'bookstore', 'mall', 'theatre'])
      -1
      """
output:     for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1