input: from typing import List
  
  def linearSearch(array: List[str], search_item: str) -> int:
      """Implement a linear search algorithm to search for an item in a given array of strings.
      >>> linearSearch(['school', 'hospital', 'bookstore', 'mall', 'theatre'], 'bookstore')
      2
      >>> linearSearch(['school', 'hospital', 'bookstore', 'mall', 'theatre'], 'library')
      -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