input: 
  def linearSearch(search_item):
      """ Function to perform a linear search through a predefined array.
      >>> linearSearch('bookstore')
      2
      >>> linearSearch('library')
      -1
      """
      array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1
  
output:     array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1