Package + static member + code block + internal class

1, Package 1. In order to better manage classes, collect multiple classes into a group and become a software package Package is the embodiment of the encapsulation mechanism of classes and interfaces. It is a better management of classes or interfacesClasses with the same name are not allowed in the same package, but they can exist in differe ...

Posted by ayfine on Sun, 19 Sep 2021 18:08:53 +0200

Map interface overview

1 Map interface Map and Collection have no inheritance relationship The Map collection stores data in the form of key and value: key value pairs Both key and value are reference data types. Both key and value are memory addresses of storage objects. Key plays a leading role, and value is an accessory of key. Common methods in Map interf ...

Posted by sunil.23413 on Mon, 06 Sep 2021 05:14:54 +0200