input: Write a function to sort a list of strings based on their length. The input is a list of strings, and the output should be the sorted list of strings. If the input list is empty, it should return the empty list.
  assert sort_strings_by_length(["Hello","World!","Good","Morning"])==["Good", "Hello", "World!", "Morning"]
  assert sort_strings_by_length(["apple", "banana", "cherry"])==["apple", "cherry", "banana"]
  assert sort_strings_by_length(["a", "bb", "ccc", "dddd"])==["a", "bb", "ccc", "dddd"]
  assert sort_strings_by_length([])==[]
output: def sort_strings_by_length(strings):
      return sorted(strings, key=len)