ios - NSUserDefault , Alloc init 与标准 Userdefault

Question

我很困惑

之间有什么区别

NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];


和

NSUserDefaults *userDefault = [[NSUserDefaults alloc] init];


谁能帮帮我……

提前致谢

Answer 1

NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];

the above line gives you the singleton object by using the class method standardUserDefaults the object received by this method is allocated single memory throughout the application.

NSUserDefaults *userDefault = [[NSUserDefaults alloc] init];

this will gives you the new object, each object is allocated a different memory and deallocated when object scope is finished.

如果您想在整个应用程序中存储和使用该值，那么最好使用单例对象，当您删除您的应用程序时，它将被释放