既然可以使用 NSUserDefaults，为什么还要使用 singleton 在多个视图控制器之间共享数据？

Question

Any thoughts on this?

Thanks for shedding some light on this.

Answer 1

NSUserDefaults is ready made database provided to us. If we use it, we are saving things in database and making fetch operation.

If you want your data to be persistent then use NSUserDefaults and/or your own database.

If you want to share data globally and dont want it to be persistent then use singleton class.

It is based on our requirement if we want a shared class (singleton class) or a database (NSuserDefaults).