Java sorting methods--list, arrays, "custom" inherit comparable and comparator

(i) List and array

①list default Sort code:

public static void Main (string[] args) {    list<string> List = new arraylist<> ();    List.add ("A-li");    List.add ("No B Settling");    List.add ("Hee X Hee");    List.add ("One Y One");    List.add ("Pass C");    List.add ("East D West");    List.add ("E-blossoming ear");    List.add ("min f");    for (int i=0;i<list.size (); i++) {        System.out.print (List.get (i));    }    Descending "in the order of the existing list----output from back to forward"    System.out.println ("descending");    Collections.reverse (list);    for (int i=0;i<list.size (); i++) {        System.out.print (List.get (i));    }    According to the list now order---from going after reading  a y one not B Andingdong D West C Recursive f Number of the X-ear e duo a Li    System.out.println ("ascending");    Collections.sort (list);    for (int i=0;i<list.size (); i++) {        System.out.print (List.get (i));    }    System.out.println ("in alphabetical order");    Sort  ABCDEFG So come the "initials"    Collections.sort (List,collator.getinstance (Locale.china));    for (int i=0;i<list.size (); i++) {        System.out.print (List.get (i));}    }

②: Array:

String[] names = {"A li", "Put B", "A Li", "D to", "Amount E", "D to", "a b li"};//should be based on the ASCII code so Arrays.sort (names); System.out.println (arrays.tostring (names)); Arrays.sort (Names,collator.getinstance (Locale.china));//According to the Chinese alphabet, first pinyin is compared with the first letter, then the second letter pinyin. System.out.println (arrays.tostring (names));

(ii) Custom sorting:

① implements the comparable interface, which compares items within the class.

public class Test1 implements comparable {/* * 1. Implement comparable interface * override int compareTo (Object o) method * */Private St    ring name;    Private Integer age;    Public String GetName () {return name;    } public void SetName (String name) {this.name = name;    } public Integer Getage () {return age;    public void Setage (Integer age) {this.age = age;        } public Test1 (String name, Integer age) {this.name = name;    This.age = age;        } @Override public int compareTo (Object o) {Test1 sutdent = (Test1) o;        int age1 = Sutdent.getage ();    Return This.age.compareTo (AGE1);        } public static void Main (string[] args) {list<test1> students = new arraylist<> ();        Test1 S1 = new Test1 ("11", 11);        Test1 s2 = new Test1 ("12", 12);        Test1 s3 = new Test1 ("13", 13);        Test1 S4 = new Test1 ("14", 14);        Students.add (S1);        Students.add (S4);       Students.add (S2); Students.add (S3);        Students.add (S2);        Reverse only reverses collections.reverse (students);        for (Test1 t:students) {System.out.print (T.getage () + "");        }//Call the Int property of your own class to compare collections.sort (students);        for (Test1 t:students) {System.out.print (T.getage () + "");    } System.out.println (""); }}

② implements Comparator interface , class peripheral comparison items .

public class Test1 implements comparator<test1> {/* * 1. Implement comparable interface * override int compareTo (Object o) method * */    private String name;    Private Integer age;    Public String GetName () {return name;    } public void SetName (String name) {this.name = name;    } public Integer Getage () {return age;    public void Setage (Integer age) {this.age = age;        Public Test1 () {} public Test1 (String name, Integer age) {this.name = name;    This.age = age;    } @Override public int compare (Test1 O1, Test1 O2) {return o1.age.compareTo (o2.age);        } public static void Main (string[] args) {Test1 s1=new Test1 ("Small 1", 11);        Test1 s3=new Test1 ("Small 3", 13);        Test1 s2=new Test1 ("Small 2", 12);        Test1 s4=new Test1 ("Small 4", 14);        Array.adlist is a fixed-length set.        List<test1> students=arrays.aslist (S1,S3,S2,S4);        for (Test1 s:students) {System.out.print (s.age+ "");      }  System.out.println ("post-sorting");        Collections.sort (Students,new Test1 ());        for (Test1 s:students) {System.out.print (s.age+ ""); }

      }    }

Java sorting methods--list, arrays, "custom" inherit comparable and comparator