Of this abstraction. The values for getRadius() or getCircumference() in the above instance could possibly be saved specifically, or they may be calculated, it will not subject into the caller; the setters might or might not have Uncomfortable side effects; it does not subject to your caller. 近年来这方面的研究开发主要是围绕结构 、 合成 https://builderflooroldgurgaon.blogspot.com/