If the object argument is null, you need to generate a null accessor for the type.

如果对象参数为空，您需要为这个类型生成一个空访问器。

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Unfortunately, many designers have still not learnt that the special null pointer or null object is an equally bad idea.

遗憾的是，许多设计者并没有认识到空指针或空对象带来的危害。

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Otherwise, there can be confusion over whether an empty array is a null object, an array with no elements, or an array with a single object containing null or empty values.

否则，可能对一个空数组是null对象还是没有任何元素的数组，亦或带有一个对象且此对象包含null或空值的数组产生混淆。

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