Comparable and comparator implementation object comparisons in Java

1. Sorting by comparable

Package Comparable;import Java.util.arrays;public class Comparableuser implements comparable<comparableuser> {p    Rivate String ID;    private int age;        Public Comparableuser (String ID, int age) {this.id = ID;    This.age = age;    } public int Getage () {return age;    public void Setage (int.) {this.age = age;    } public String GetId () {return id;    } public void SetId (String id) {this.id = ID;         } public int compareTo (Comparableuser o) {return this.age-o.getage ();    Return ((Comparableuser) O). Getage ()-this.age; }/** * Test method * * public static void Main (string[] args) {comparableuser[] users = new comparableuser[ ] {new Comparableuser ("u1001"), New Comparableuser ("u1002"), New Com        Parableuser ("u1003", 21)}; Arrays.sort (users);//Sort objects for (int i = 0; i < users.length; i++) {ComparableUser user = Users[i];        System.out.println (User.getid () + "" + user.getage ()); }    }}

2. Sorting by implementing comparator

Package Comparable;import Java.util.arrays;import java.util.comparator;class User {private String ID;        private int age;          Public User (String ID, int age) {this.id = ID;      This.age = age;      } public int Getage () {return age;      public void Setage (int.) {this.age = age;      } public String GetId () {return id;      } public void SetId (String id) {this.id = ID;          }}public class Usercomparator implements Comparator {public int compare (object arg0, object arg1) {      return (user) arg0. Getage ()-((user) arg1). Getage (); }/** * Test method * * public static void Main (string[] args) {user[] users = new user[] {new Us          ER ("u1001"), New User ("u1002"), New User ("u1003", 21)};          Arrays.sort (Users, New Usercomparator ()); for (int i = 0; i < users.length; i++) {User user = UseRs[i];          System.out.println (User.getid () + "" + user.getage ());   }      }}

Recommended Use cases:

Package Comparable;import Java.util.arrays;import java.util.comparator;class User {private String ID;    private int age;    private int score;        Public User (String ID, int age, int score) {this.id = ID;        This.age = age;    This.setscore (score);    } public int Getage () {return age;    public void Setage (int.) {this.age = age;    } public String GetId () {return id;    } public void SetId (String id) {this.id = ID;    } public int Getscore () {return score;    } public void SetScore (int score) {This.score = score; }}public class Usercomparator implements comparator<user> {public int compare (user arg0, user arg1) {if (        Arg0.getage () <arg1.getage ()) return 1;        else if (Arg0.getage () >arg1.getage ()) return-1;        else if (Arg0.getscore () <arg1.getscore ()) return-1; else if (Arg0.getscore () >arg1.getscore ()) return1;    return 0;                 }/** * Test method * * public static void Main (string[] args) {user[] users = new user[] {        New User ("u1001", "Max"), New User ("u1002", "25"), New User ("U1003", 91)};        Arrays.sort (Users, New Usercomparator ());            for (int i = 0; i < users.length; i++) {User user = Users[i];        System.out.println (User.getid () + "" + user.getage () + "" + User.getscore ()); }    }}

Comparable and comparator implementation object comparisons in Java