把数学对象分为不同种类分别考察,是数学研究的重要方法。正确分类是完整解题的基础。分类应当符合两条原则:一是应该按同一标准进行;二是应当不重复,不遗漏。分类后,对各种情况分别进行研究,得出不同情况下的结论,这就是讨论。本文对中考试题中常见的函数分类讨论题作一简单介绍。 Dividing mathematical objects into different categories is an important method of mathematical research. Correct classification is the basis for a complete solution. The classification should conform to two principles: First, it should be conducted according to the same standard; second, it should not be repeated and should not be omitted. After the classification, each case was studied separately and conclusions were drawn under different circumstances. This is the discussion. This article gives a brief introduction to common functional classification discussion topics in the mid-term exam questions.