Of this abstraction. The values for getRadius() or getCircumference() in the above mentioned example could possibly be stored instantly, or they could be calculated, it would not subject towards the caller; the setters could or might not have side effects; it would not matter towards the caller. 近年来这方面的研究开发主要是围绕结构 、 合成 https://affordablehousinginbhiwadi.blogspot.com