基本解释[数学]类的零集英汉例句双语例句Also, many times member variables of a class that point to other classes simply need to be set to null at the appropriate time.此外，您常常需要在适当的时候将指向其他类的类成员变量设置为 null。null set of class更多例句词组短语短语null set of class nf NF 类零集null set of class更多词组专业释义数学类的零集