<pre><code class="language-python">class Pet: def init(self, n, a): self._name = n self._age = a def get_name(self): return self._name def birthday(self): self._age += 1 if name == "main": cat = Pet("奶茶", 2) print(cat.get_name()) # ① cat.birthday() # ② cat._name = "大橘" # ③ print(cat.get_name()) # ④</code></pre>