making comparator java

Here is a brief introduction to Java's comparable internal comparator and comparator external comparator usage implementationSo let's do a sort of between objects, first build a model or call Javaben. As follows:The use of the 1.Java comparable internal comparator is impleme

defined as follows: Package java.util; Public interface comparator Description1. If a class implements the comparator interface: it must implement the CompareTo (t O1, T O2) function, but it may not implement the Equals (Object obj) function.Why not implement the Equals (Object obj) function? Because any class, the default is already implemented equals (Object obj). All classes in

[Common Java class libraries] _ notes on comparator (comparable and comparator) Objectives of this chapter:Understanding the use of comparable comparison InterfacesUnderstand the basic sorting principle of ComparatorUnderstanding the use of comparator comparison Interfaces Comparable Interface You can directly use the

second list and comparer method to sort key or value, if the comparator returns 0, the value is the same as the reverse value, how much output. (If a friend knows why, please leave a message under the article, thank you)HashMap sortWe are all HashMap values are not sequential, he is based on key hashcode to achieve. How are we going to achieve this sort of unordered hashmap? Referring to the value of TreeMap, we can also implement HashMap sort.Sort b

O2, returns 0 for O1 and O2 equal, and returns a positive number that represents O1 greater than O2.Publicclasstreesettest{publicstaticvoidmain (String []args) {treesettree=newtreeset ( Newmycomparator ()); tree.add (NewPerson); tree.add (Newperson); tree.add (Newperson); tree.add (new Person ()); System.out.println (tree); //[20,21,24,33]}}classperson{ intage;stringname;public person (intage) {this.age=age; }Nbsp;publicstringtostring () {return string.valueof (this.age);}}classmycomparatorimpl

1. TreeSet guarantee Element uniqueness and comparator ordering principle and code implementation (comparator sort)(1)Student. Java:1 Packagecn.itcast_07;2 3 Public classStudent {4 PrivateString name;5 Private intAge ;6 7 PublicStudent () {8 Super();9 }Ten One PublicStudent (String name,intAge ) { A Super(); - Thi

Comparator is located under Package Java.util, the comparator, which is defined in the collection outside the sorting.Comparable is located under Package Java.lang, which represents the comparison of the current object, and is the implementation of sorting within the collection.Comparable represents an object that supports ordering internally (such as the String class, the integer class, the internal imple

Java _ SET _ ArrayLish Comparator comparison sorting note, comparator sorting Import java. util. ArrayList;Import java. util. Collections;Import java. util. Comparator; Class Teacher_M

binarytree{Class node{//Declaration of a Node classprivate comparable data; Save the specific contentPrivate Node left; Save ZuoziPrivate Node right; Save Right subtreePublic Node (comparable data) {This.data = data;}public void AddNode (Node newNode) {Make sure it's on the Zuozi or right subtree.if (NewNode.data.compareTo (this.data) if (this.left==null) {This.left = NewNode; Set the new node directly to Zuozi}else{This.left.addNode (NewNode); Continue judging down}}if (NewNode.data.compareTo

Public intCompare (Object O1, Object O2) {//TODO auto-generated Method StubPresondemo p1=(Presondemo) O1; Presondemo P2=(Presondemo) O2; inttemp=p1.getname (). CompareTo (P2.getname ()); returnTemp==0?p1.getage ()-p2.getage (): temp; }}Treesetdemo PackageCn.stat.p6.arraylist.demo;ImportCn.stat.p5.person.demo.PresonDemo;ImportJava.util.Iterator;ImportJava.util.TreeSet;Importjava.util.ArrayList; Public classTreesetdemo { Public Static voidMain (string[] args) {TreeSet ts=NewTreeSet (Newcompartorb

". Comparator Introduction Comparator is the comparator interface. If we need to control the order of a class, and the class itself does not support sorting (that is, not implementing the comparable interface), then we can create a "comparer for that class" to sort. This "comparer" only needs to implement the comparator