In Objective-C, what's the advantage of having a singleton over a class method?

Question

如上所述，但是要小心，我只对Objective-C上下文感兴趣，因此没有必要指出单例优于静态方法的优点。

Answer 1

I would say nothing. Singletons are often considered bad practice and this applies to Obejctive-C as well. One thing that might make singletons a better solution than class methods is that singletons are proper instances that can access instance variables, so if one needs the class to store data in ivars, singletons can be a solution. (But well, even implementing singletons often requires using static global or local variables - so strictly speaking, you can't really avoid them entirely, at most you can reduce their number to one.)

Answer 2

One significant advantage is class methods in Objective-C can't hold onto any data (unless declared as static within the method). Whereas with a singleton, you have access to all of the data of the single-instance