text: # Write a function that takes in a number, string, list, or dictionary
  # and returns its JSON encoding. It should also handle nulls.
  
  # For example, given the following input:
  
  # [None, 123, ["a", "b"], {"c":"d"}]
  # You should return the following, as a string:
  
  # '[null, 123, ["a", "b"], {"c": "d"}]'
  
  import json
  
  def json_encode(obj):
      return json.dumps(obj)
  
  print(json_encode([None, 123, ["a", "b"], {"c":"d"}]))