Modification of Java:list Collection

The implementation class of the list is ArrayList; Specific code:

List < generic > collection name; Create a list collection

construct method: Public

class name () {
class name a1= collection name. arraylist< generics > ();

}

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

Import java.util.List; * * Deposit Alternative courses/public class Listtest {public list coursetoselect;//create a new List container for alternate course public listtest () {This
		. Coursetoselect = new ArrayList ();//cannot instantiate the list, but it can instantiate its subclasses, then pass in the list collection}/* Add and view */public void Testadd () { Add the element//First Add method to the collection using 2 Add methods, the last course CR1 = new Course ("1", "Data structure") added to the collection;//Create Course Object Coursetoselect.add (CR1) ;//Call the Add method to pass the course object into/* * After successfully adding the course, the user needs to be printed feedback feedback information needs to be extracted from the information in the call to the PRINT statement////Get method to remove the stored information from the container. 0 for subscript, object in container is obj ECT type, you need to force type conversion Course TEMP = (course) coursetoselect.get (0);//Remove the specified element and force type conversion before assignment System.out.println ("successfully added

		Course: "+ temp.id +". "+ Temp.name);
		The second Add method course Cr2 = new Course ("2", "C language");//Create Course Object Coursetoselect.add (0, CR2);//Use the Add method to add the object containing the course information CR2 to the specified location Course Temp2 = (course) coursetoselect.get (0)//remove element System.out.println at the specified location within the container ("course added successfully: + temp2.id +". "+ Temp2.nam
e);		
Add elements repeatedly, the compiler does not error, the description can be repeated. Coursetoselect.add (0, CR1);//Use the Add method to add an object CR2 containing course information to the specified location course temp0 = (course) coursetoselect.get (0);
		
		Remove the element System.out.println the specified position within the container ("successfully added course: + temp0.id +". "+ Temp0.name); * * Attempt to add an object to a nonexistent element position * * * Course CR3 = new Course ("3", "Eclipse")//* Create Course Object Coursetoselect.add (4, * CR3 //Use the Add method to add the object Cr2 containing course information to the specified location to run the bug,bug reason: array subscript out of bounds///2 AddAll Method Bulk add element//First AddAll method, add the whole collection into, and can only add list class, so You need to convert the course class to List class course[] course = {New Course ("3", "Discrete Math"), New Course ("4", "assembly language")};//create an array containing 2 course objects Cou Rsetoselect.addall (Arrays.aslist (course)), after converting the course array to the list class add in Course Temp3 = (course) coursetoselect.get (2); /remove element Course Temp4 = (course) coursetoselect.get (3)//remove element System.out.println ("Two courses successfully added: + Temp3.id +". "+ Temp

		3.name + ";" + Temp4.id + "." + Temp4.name);
		The second AddAll method course[] Course2 = {New Course ("5", "Higher Mathematics"), New Course ("6", "College English")}; Coursetoselect.addall (2,arrAys.aslist (COURSE2)), add Course2 to the list after conversion to the specified location course TEMP5 = (course) coursetoselect.get (2);//Remove the element course TEMP6 = ( Course) Coursetoselect.get (3);//remove Element System.out.println ("Two courses successfully added: + Temp5.id +". "+ Temp5.name +"; "+ Temp6.id +
	"." + Temp6.name);
		* * * View * Get all the elements in the list * use for loop calendar/public void Testget () {int size= coursetoselect.size ();//Get the length of the list collection
		SYSTEM.OUT.PRINTLN ("There are courses to be selected:");
			for (int i=0;i<size;i++) {Course CR = (course) coursetoselect.get (i);
		System.out.println (Cr.id + "." + Cr.name); }/* * through iterator (iterator) Calendar list * */public void Testterator () {iterator it=coursetoselect.iterator ();//iter
		Ator is also an interface class that can only be instantiated by calling its subclasses iterator System.out.println ("There are courses to be selected (via iterator access)"; while (It.hasnext ()) {//hasnext method to determine if there are any elements in the list, return the Truth Course cr= (course) it.next ();
		M.out.println (Cr.id + "." + Cr.name); }/* * iterators are used to go through the elements of the collection and cannot store any data/* * Access to the collection element through the For each method/public void TeStforeach () {System.out.println ("There are the following courses to choose from:"); For (object Obj:coursetoselect) {//Define an object type variable obj, that is, all elements of the Calendar list Course er= (course) obj;//take out the element, and when a course is stored it is ignored.
		A type conversion System.out.println (Er.id + "." + Er.name) is required for removal.
	}/* * Use the Set method to modify the specified element */public void testmodify () {Coursetoselect.set (4, New Course ("7", "Gross")); * * * Use the Remove method to remove the specified element * The Remove method has two, an incoming variable name, an incoming array subscript, here is only a second example */public void Remove () {//Course cr= (course) c
Oursetoselect.get (4);//Remove, cast type//System.out.println ("I am Course:" +cr.id + "." + cr.name+ "" I Will be deleted ");
Coursetoselect.remove (CR)////////////////////////////////////////////////////
System.out.println ("delete succeeded"); Testforeach ()//Call iterator Output course//Bulk Delete element course[] courses= {(course) Coursetoselect.get (4), (course) Coursetoselect.get (
		
		5)};
		Coursetoselect.removeall (Arrays.aslist (courses));//to the list array System.out.println ("delete succeeded") before passing in;
	Testforeach (); * * * Using the bulk delete element */public void Testtype () {System.out.println ()Try to pass the list to something else ");
	Coursetoselect.add ("Passing Strange things to the list");
		///Create Main method test run code public static void Main (string[] args) {Listtest lt = new Listtest ();
		Lt.testadd ();
		Lt.testmodify ();
		Lt.testforeach ();
Lt.remove ();
Lt.testtype ();
Lt.testget ();
Lt.testterator ();
Lt.testforeach ();
		
	Lt.removeall ();
 }
}