input:                         
  from typing import List
  
  def linearSearch(array: List[str], search_item: str) -> int:
      """Search for an item in the given array using a linear search algorithm.
      If the item is found, return its position in the array. If the item is not found, 
      return -1.
  
      >>> array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      >>> linearSearch(array, 'bookstore')
      2
      >>> linearSearch(array, 'library')
      -1
      """
output:     for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1