Code Practice--java-7-Collection Class __ajax

Welcome to visit the blog Base Code List interface

Import Java.util.Iterator;
Import java.util.LinkedList;
Import java.util.List;
public class Collectiondemo {public
    static void Main (string[] args) {
        String a= "A", b= "B", c= "C", d= "D", e= "E"; 
  list<string> List = new linkedlist<string> ();
        List.add (a);
        List.add (e);
        List.add (d);
        iterator<string> firstiterator = List.iterator ();
        System.out.println ("The elements in the set before the modification are:");
        while (Firstiterator.hasnext ()) {
            System.out.print (Firstiterator.next () + "  ");
        }
        List.set (1,b);
        List.set (2,c);
        Iterator<string> it = List.iterator ();
        System.out.println ();
        System.out.println ("The elements in the modified set are:");
        while (It.hasnext ()) {
            System.out.print (It.next () + "  ");
        }
    }
}

List Index

Import java.util.ArrayList;
Import java.util.LinkedList;
Import java.util.List;
public class Collectiondemo {public
    static void Main (string[] args) {
        String a= "A", b= "B", c= "C", d= "D", apple= "a Pple ";
        list<string> list = new arraylist<string> ();
        List.add (a);
        List.add (apple);
        List.add (b);
        List.add (apple);
        List.add (c);
        List.add (apple);
        List.add (d);
        SYSTEM.OUT.PRINTLN (list);
        System.out.println ("Apple's first occurrence of index position is:" + list.indexof (apple));
        System.out.println ("Apple's last occurrence index position is:" + list.lastindexof (apple));
        System.out.println ("B" the index position to appear for the first time is: "+ list.indexof (b));
        System.out.println ("B Last occurrence of index position is:" + list.lastindexof (b));
    }

Set interface
Using collections to remove duplicates

Import java.util.ArrayList;
Import Java.util.HashSet;
Import Java.util.Iterator;
Import java.util.List;
Import Java.util.Set;

public class Collectiondemo {public
    static void Main (string[] args) {
        list<string> List = new arraylist< String> ();
        List.add ("Apple");
        List.add ("pear");
        List.add ("banana");
        List.add ("Apple");
        set<string> set = new Hashset<string> ();
        Set.addall (list);
        Iterator<string> it = Set.iterator ();
        System.out.println ("The elements in the collection are:");
        while (It.hasnext ()) {
            System.out.print (It.next () + "  ");
        }
    }
}

Map interface

Import Java.util.HashMap;
Import Java.util.Map;

public class Collectiondemo {public
    static void Main (string[] args) {
        map<string, string> Map = new HashMap <string, string> ();
        Map.put ("1", "Apple");
        Map.put ("2", "pear");
        Map.put ("3", "orange");
        for (int i=1; i<=map.size (); i++) {
            System.out.println ("+i+" element is: "+map.get (" "+i+"));}}

Implementation class for List interface

Import java.util.ArrayList;
Import java.util.List;

public class Test {public
    static void Main (string[] args) {
        list<string> List = new arraylist<string> ();
        int i = (int) (Math.random () * (List.size ()-1));
        List.add ("a");
        List.add ("B");
        List.add ("C");
        SYSTEM.OUT.PRINTLN ("Randomly acquiring elements in an array:" + list.get (i));
        List.remove (2);
        System.out.println (the element in the array is: "After the element that has the index is ' 2" is removed from the array);
        for (int j=0; j<list.size (); j + +) {
            System.out.print (List.get (j) + "");}}}

Implementation classes for SET interfaces

Import Java.util.HashSet;
Import Java.util.Iterator;

Import Java.util.Set; public class Collectiondemo {public static void main (string[] args) {set<people> hashset = new HashSet
        <People> ();
        Hashset.add (New people ("Chen classmate", 201101));
        Hashset.add (New people ("Wang classmate", 201102));
        Hashset.add (New people ("classmate Li", 201103));
        Iterator<people> it = Hashset.iterator ();
        System.out.println ("The elements in the collection are:");
            while (It.hasnext ()) {People person = it.next ();
        System.out.println (Person.getname () + "" + Person.getid_card ());
    }} class People {private String name;
    Private long Id_card;
        Public people (String name, long id_card) {this.name = name;
    This.id_card = Id_card;
    Public long Getid_card () {return id_card;
    } public void Setid_card (long id_card) {this.id_card = Id_card;
    Public String GetName () {return name;
}    public void SetName (String name) {this.name = name; }
}

Instance-Traversal of ArrayList using a for loop

Import java.util.ArrayList;
Import java.util.List;

public class Test {public
    static void Main (string[] args) {
        list<integer> List = new ARRAYLIST<INTEGER&G t; ();
        for (int i=0; i<10; i++) {
            list.add (i);
        }
        System.out.println ("Elements in the list:" + lists);
        System.out.println ("Odd ordinal element in the list:");
        for (int i=1; i<list.size (); I +=2) {
            System.out.print (list.get (i) + "  ");
        }
    }

The creation and use of iterators

Import java.util.ArrayList;
Import java.util.Collections;

Import Java.util.ListIterator; public class Test {public static void main (string[] args) {arraylist<integer> array = new ARRAYLIST&LT
        ;integer> ();
        add element Collections.addall (array, 1,2,3,4,5,6) to the collection using the tool method in the Collections class AddAll ();
        System.out.println ("Elements in the collection:" + array);
        The Listiterator object listiterator<integer> iterator = Array.listiterator () is obtained by using the method without parameters.
        For the initial position, decide whether to have the next element boolean hasnext = Iterator.hasnext ();
        System.out.println ("Whether the collection has the next element:" + Hasnext);
        For the initial position, determine if there is a previous element Boolean hasprevious = Iterator.hasprevious ();
        System.out.println ("Whether the collection has the previous element:" + hasprevious);
        int next = Iterator.next ();
        System.out.println ("Get the next element of the collection:" + next);
        int nextindex = Iterator.nextindex ();
        System.out.println ("Gets the index of the next element of the collection:" + Nextindex);
        int previous = Iterator.previous (); System.out.prinTLN ("Get the first element of a set:" + previous);
        int previousindex = Iterator.previousindex ();
        System.out.println ("Gets the index of the previous element of the collection:" + Previousindex);
        Iterator.add (7);
        System.out.println ("Add the set after element 7 to the set:" + array);
        Iterator.next ();
        Iterator.set (12);
        System.out.println ("The next element to be obtained is modified to the set after 12:" + array);
        Iterator.remove ();
    System.out.println ("will get the next element removed after the collection:" + array); }
}

Instance-iterator traversal ArrayList

Import java.util.ArrayList;
Import Java.util.Iterator;
Import java.util.List;

public class Test {public
    static void Main (string[] args) {
        list<integer> List = new ARRAYLIST<INTEGER&G t; ();
        for (int i=0; i<10; i++) {
            list.add (i);
        }
        System.out.println ("All elements in the list:");
        for (iterator<integer> it = List.iterator (); It.hasnext ();) {
            System.out.print (It.next () + "");}}

Instance-Listiterator traversal ArrayList

import java.util.ArrayList; import java.util.List; import java.util.ListIterator; public class Test {public static void main (string[] args) {list<integer> List = new Arraylist<integ
        Er> ();
        for (int i=0; i<10; i++) {list.add (i);
        } System.out.println ("All elements in the list are:" + list);
        SYSTEM.OUT.PRINTLN ("the element in reverse output list:");
        Listiterator<integer> li = List.listiterator ();
        For (Li=list.listiterator (); Li.hasnext ();) li.next (); 
            for (; li.hasprevious ();)
    System.out.print (li.previous () + ""); }
}