Design: Passing on class instances or using singletons?

The problem with singletons is that they make it harder to mock and unit test your application. You should decouple your dependencies; and if you do somehow need a singleton (which should be very, very rare) then consider having the singleton implement an interface that you can mock for testing purposes.

Whenever I'm tempted to use a singleton, I re-read Global Variables are Bad and consider whether the convenience is really worth putting up with this (slightly) paraphrased list of problems.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.