Sorting Java Collection classes and Java Collection classes

Sorting Java Collection classes and Java Collection classes

A collection class is mainly used to store and hold other data. Therefore, a collection class is also called a container class. All collection classes are under the java. util package.

The Collection class is different from the array. The array element can be either a value of the basic type or an object (in fact, the referenced variable of the object is saved), while the set can only save the object.

Java's collection classes mainly consist of Collections and Map. Collections and Map are the root interfaces of the Java Collection framework. The Inheritance relationships of Java integration are as follows:

Inheritance relationship of Collection set Columns

Inheritance relationship of Map interface

2. Collection interface and Iterator interface 1. Collection Interface

The collection interface is the parent interface of the List, set, and Queue interfaces. The methods defined in this interface can be used to operate the Set set