//************************** //|| ARRAY LIST IN JAVA ||| //-------------------------- import java.util.*; public class Program{ public static void main(String[] args){ //**************************** //|| CREATING AN ARRAY LIST || //---------------------------- ArrayList myarraylist=new ArrayList(); ArrayList myintegerlist=new ArrayList(); ArrayList myboollist=new ArrayList(Arrays.asList(new Boolean[2])); ArrayList mydoublelist=new ArrayList(); //*************************************** //checking the size of the array list ||| //--------------------------------------- System.out.println("INITIAL SIZE OF THE ARRAY LISTS"); System.out.println("STRING LIST:"+myarraylist.size()); System.out.println("INTEGER LIST"+myintegerlist.size()); System.out.println("BOOLEAN LIST:"+myboollist.size()); System.out.println("DOUBLE LIST:"+mydoublelist.size()); System.out.println(); //********************************** //||||| ADDING ELEMENTS |||||||||||| //---------------------------------- //WE SHOULD FOLLOW THE FOLLOWING GUIDELINES TO ADD THE ELEMENTS TO THE //ARRAY LIST //add() takes the parameters that should be added to the ArrayList //NameOfYourArrayList.add("your item"); //on the above i have created the arraylist to store the strings //so to the add method i have to specify the my data in "your data" //if we created the arraylist for number we should specify just the numbers myarraylist.add("welcome to"); myarraylist.add("java"); myarraylist.add("collections"); myintegerlist.add(1); myintegerlist.add(0); myintegerlist.add(2); myintegerlist.add(3); myintegerlist.add(4); myintegerlist.add(5); Collections.fill(myboollist,Boolean.FALSE); Collections.fill(myboollist,Boolean.TRUE); mydoublelist.add(3.3333); mydoublelist.add(9.9999); mydoublelist.add(99.999); //*************************************** //checking the size of the array list ||| //--------------------------------------- System.out.println("SIZE OF THE ARRAY LIST AFTER ADDING OF ELEMENTS"); System.out.println("STRING LIST:"+myarraylist.size()); System.out.println("INTEGER LIST"+myintegerlist.size()); System.out.println("BOOLEAN LIST:"+myboollist.size()); System.out.println("DOUBLE LIST:"+mydoublelist.size()); //********************************************************** //||||||| DISPLAYING THE CONTENTS OF THE ARRAYLSITS ||||||||| //---------------------------------------------------------- System.out.println(); System.out.println("PRINTING THE CONTENTS"); System.out.println("STRING LIST:"+myarraylist); System.out.println("INTEGER LIST:"+myintegerlist); System.out.println("BOOLEAN LIST:"+myboollist); System.out.println("DOUBLE LIST:"+mydoublelist); //******************************************* //||||||| removing the elements ||||||||||||| //------------------------------------------- //******************************** //UNCOMMENT TO REMOVE THE ELEMENTS //-------------------------------- //we can specify the index or the value diretly to the remove method //REMOVES THE ITEM AT SPECIFIED VALUE //myarraylist.remove(0); //REMOVES THE SPECIFIED ITEM //myaaraylist.remove("java"); //it removes the element at the index 0 System.out.println(); System.out.println("PRINTING THE CONTENTS"); System.out.println("STRING LIST:"+myarraylist); System.out.println("INTEGER LIST:"+myintegerlist); System.out.println("BOOLEAN LIST:"+myboollist); System.out.println("DOUBLE LIST:"+mydoublelist); System.out.println(); //********************************* //||||| TRAVERSING THE LIST |||||||| //---------------------------------- System.out.println("TRAVERSING THE LIST"); System.out.println(); for(String item:myarraylist){ System.out.print(item+" "); } System.out.println(); //traversing the list by for loop //if we want to traverse the elements of arraylist using for loop //we need to use the get() function for(int i=0;i myarraylistthree= new ArrayList(myarraylist.subList(2, 3)); System.out.println("\n\nPRINTING THE SUBLIST\n"); System.out.println(myarraylistthree); ArrayList myarraylistfour=new ArrayList(myarraylist.subList(1,4)); System.out.println("\n\nPRINTING THE SUBLIST\n"); System.out.println(myarraylistfour); //********************************* //|||||| splititerator |||||||||||| //-------------------------------- //Split iterator breaks the list into small parts and these //small parts are processed in the parallel for our applications //we use splititerator less in real world projects //split iterator will work normally as the iterator //collection class of the JAVA provides the two methods //to use the splititerator //1)default stream() //2)parallelStream() //those two methods are used to process the elements in the parallel //Collection.java //default Stream stream() { //return StreamSupport.stream(spliterator(), false); //} //default Stream parallelStream() { // return StreamSupport.stream(spliterator(), true); //} //splititerator methods //we can use splititerator provided methods to process the data in parallel //tryAdvance():used for parallel processing we can iterate elements in different threads //forEachRemaining():to iterate elements sequentially in a single thread //trySplit():partition the spliterator, if possible. //cobines the hasNext() and next() into one method //int characteristics(): //list of characters of splititerator //1)ORDERED //2)DISTINCT //3)SORTED //4)SIZED //5)NONNULL //6)IMMUTABLE //7)CONCURRENT //8)SUBSIZED //long estimateSize(): //retruns the number of elements pending on traversal //which was done by forEachReemaining() //default void forEachRemaining(Consumer action): //does the given action on each remaining element sequentially in the current thread //until all elements have been processed //or //until action throws an exception // //******************************* //Spliterator characteristics() || //------------------------------- System.out.println("\n\nSPLIT ITERATOR CHARACTERISTICS METHOD\n"); Spliterator myspliterator = myarraylist.spliterator(); int expected = Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; System.out.println(myspliterator.characteristics() == expected); //true if (myspliterator.hasCharacteristics(Spliterator.ORDERED)) { System.out.println("ORDERED"); } if (myspliterator.hasCharacteristics(Spliterator.DISTINCT)) { System.out.println("DISTINCT"); } if (myspliterator.hasCharacteristics(Spliterator.SORTED)) { System.out.println("SORTED"); } if (myspliterator.hasCharacteristics(Spliterator.SIZED)) { System.out.println("SIZED"); } if (myspliterator.hasCharacteristics(Spliterator.CONCURRENT)) { System.out.println("CONCURRENT"); } if (myspliterator.hasCharacteristics(Spliterator.IMMUTABLE)) { System.out.println("IMMUTABLE"); } if (myspliterator.hasCharacteristics(Spliterator.NONNULL)) { System.out.println("NONNULL"); } if (myspliterator.hasCharacteristics(Spliterator.SUBSIZED)) { System.out.println("SUBSIZED"); } //************************************************** //|||| estimateSize() and getExactSizeIfKnown() ||||| //--------------------------------------------------- System.out.println("\n\ngetEstimateSize() and getExactSizeIfKnown()\n"); System.out.println(myspliterator.estimateSize()); System.out.println(myspliterator.getExactSizeIfKnown()); //****** trySplit() ****************** System.out.println("\n\nTRY SPLIT METHOD\n"); myspliterator.forEachRemaining(System.out::println); Spliterator mysplitone=myarraylist.spliterator(); System.out.println("\n\nSPLITTING ONE\n"); mysplitone.forEachRemaining(System.out::println); //Spliterator mysplittwo=mysplitone.trySplit(); //System.out.println("\n\nSPLITTING TWO\n"); //mysplittwo.forEachRemaining(System.out::println); //throwing exception NullPointerException have to figure out //*********************************************** //|||||| adding element at a index add method ||| //---------------------------------------------- System.out.println("\n\nBEFORE ADDING\nMY ARRAY LIST\n"); System.out.println(myarraylist); //adding hello at index 0 myarraylist.add(0,"hello"); System.out.println("\n\nAFTER ADDING\nMY ARRAY LIST\n"); System.out.println(myarraylist); //**************************** //|||| addAll() ||||||||||||| //-------------------------- System.out.println("\n\nBEFORE ADD ALL\nMY ARRAY LIST\n"); System.out.println(myarraylist); //adding hello at index 0 Collections.addAll(myarraylist,"vector","collection","hashmap","collection"); System.out.println("\n\nAFTER ADDING\nMY ARRAY LIST\n"); System.out.println(myarraylist); System.out.println("\n\nBEFORE ADD ALL METHOD 2\nMY ARRAY LIST\n"); System.out.println(myarraylist); //adding hello at index 0 ArrayList mylisttwo=new ArrayList(Arrays.asList("date","time","topic")); myarraylist.addAll(0,mylisttwo); System.out.println("\n\nAFTER ADDING \nMY ARRAY LIST METHOD 2\n"); System.out.println(myarraylist); //******************************* //||||||| clear() ||||||||||||||| //------------------------------= //clear all the elements from the LIST System.out.println("\n\nBEFORE CLEARING THE LIST\n"); System.out.println(myarraylist); //uncomment to see the function of clear //myarraylist.clear(); System.out.println("\n\nAFTER CLEARING THE LIST\n"); System.out.println(myarraylist); //***************************** //|||| clone() ||||||||||||||| //--------------------------- // returns the shallow copy of the list System.out.println("\n\nCLONNING THE ARRAY LIST \n"); ArrayList myduplicatelist=new ArrayList(); myduplicatelist=(ArrayList)myarraylist.clone(); System.out.println(myduplicatelist); //**************************** //|||| CONTAINS() ||||||||||| //---------------------------- //RETURNS TRUE IF LIST CONTAINS THE GIVEN ELEMENT System.out.println("\n\nCONTAINS METHOD\n"); System.out.println("DOES LIST COTAINS JAVA:"+myarraylist.contains("java")); System.out.println("DOES LIST COTAINS RUBY:"+myarraylist.contains("ruby")); System.out.println("DOES LIST COTAINS HELLO:"+myarraylist.contains("hello")); System.out.println("DOES LIST COTAINS GO:"+myarraylist.contains("GO")); System.out.println("DOES LIST COTAINS TOPIC:"+myarraylist.contains("topic")); System.out.println("DOES LIST COTAINS JAVASCRIPT:"+myarraylist.contains("javascript")); //********************************* //||||||| ensureCapacity(); ||||||| //--------------------------------- //used to define the atleast size of the arraylist myarraylist.ensureCapacity(10); //********************** //||||| forEach() ||||||| //---------------------- System.out.println("\n\nTRAVERSING THE ARRAY LIST BY USING OF FOREACH\n"); myarraylist.forEach(item->System.out.print(item+" ")); //******************* //|||| indexOf() ||| //------------------ //to find the index System.out.println("\n\nINDEX OF METHOD\n"); System.out.println("INDEX OF JAVA:"+myarraylist.indexOf("java")); //returns -1 if not found the index System.out.println("INDEX OF RUBY:"+myarraylist.indexOf("ruby")); //************* //| isEmpty() | //------------- //RETURNS TRUE IF LIST CONTAINS NO ELEMENT System.out.println("\n\nISEMPTY\n"); System.out.println("IS MYARRAY LIST IS EMPTY"+myarraylist.isEmpty()); ArrayList dummylist=new ArrayList(); System.out.println("IS DUMMYLIST IS EMPTY"+dummylist.isEmpty()); //***************** //| ITERATOR() | //---------------- System.out.println("\n\nPRINTING THROUGH ITERATOR\n"); //iterator to traverse the element Iterator myiterator=myarraylist.iterator(); // Print the first item using iterator System.out.println(myiterator.next()); System.out.println("\n\nPRINTING ELEMETS THROUGH WHILE LOOP\n"); while(myiterator.hasNext()){ System.out.print(myiterator.next()+" "); } //********************** //||| lastIndexOf() |||| //---------------------- myarraylist.add("java"); System.out.println("\n\nPRINTING THE LAST INDEX\n"); System.out.println("LAST INDEX OF JAVA IS:"+myarraylist.lastIndexOf("java")); //************************ //||| list ITERATOR() ||| //------------------------ System.out.println("\n\nPRINTING THROUGH LIST ITERATOR\n"); //iterator to traverse the element ListIterator mylistiterator=myarraylist.listIterator(5); // Print the first item using iterator System.out.println(mylistiterator.next()); System.out.println("\n\nPRINTING ELEMETS THROUGH WHILE LOOP\n"); while(mylistiterator.hasNext()) { String myitem=mylistiterator.next(); System.out.println(myitem); } //****************** //||| REMOVEALL |||| //------------------ ArrayList myremovinglist=new ArrayList(List.of("sololearn","freecodecamp","caltech")); System.out.println("\n\nREMOVE ALL METHOD\n"); System.out.println("OUR LIST"); System.out.println(myremovinglist); //removing list //******************************* //UNCOMMENT HERE TO REMOVE ALL //----------------------------- //myremovinglist.removeAll(myremovinglist); System.out.println(myremovinglist); //******************** //||||removeIf()|||||| //-------------------- System.out.println("\n\nBEFORE REMOVE IF\n"); System.out.println(myremovinglist); System.out.println("\n\nAFTER REMOVE IF\n"); myremovinglist.removeIf(itemm->(itemm.length()>5 && itemm.length()<8)); System.out.println(myremovinglist); //************************** //||||| removeRange() |||||| //-------------------------- System.out.println("\n\nREMOVE RANGE IS PROTECTED IN JAVA \n SO USE CLEAR METHOD TO SAVE TIME\n"); //System.out.println("\n\nBEFORE REMOVE RANGE\n"); //System.out.println(myarraylist); //System.out.println("\n\nAFTER REMOVE REMOVE\n"); //myarraylist.removeRange(1,2); //System.out.println(myarraylist); //****************************** //||||| replaceAll() ||||||||||| //------------------------------ System.out.println("\n\nBEFORE REPLACE ALL\n"); System.out.println(myarraylist); System.out.println("\n\nAFTER REPLACE ALL\n"); Collections.replaceAll(myarraylist,"java","JAVA"); System.out.println(myarraylist); //WE CAN OBSERVE THAT TWO STRINGS "java" was replace with "JAVA" //*************************** //||||| retainAll() ||||||||| //=========================== //COMPARE THE TWO LISTS AND RETURNT THE SIMILAR ELEMENETS ArrayList retainlist=new ArrayList(List.of("java","hello","topic","collections","ruby","go","scala","kotlin")); System.out.println("\n\n MY ARRAY LIST\n"); System.out.println(myarraylist); System.out.println("\n\nRETAINLIST\n"); System.out.println(retainlist); System.out.println("AFTER APPLYING OF RETAIN ALL OPERATION"); retainlist.retainAll(myarraylist); System.out.println("\n\n MY ARRAY LIST\n"); System.out.println(myarraylist); System.out.println("\n\nRETAINLIST\n"); System.out.println(retainlist); //REVERSING THE ROLES myarraylist.retainAll(retainlist); System.out.println("AFTER APPLYING OF RETAIN ALL OPERATION"); retainlist.retainAll(myarraylist); System.out.println("\n\n MY ARRAY LIST\n"); System.out.println(myarraylist); System.out.println("\n\nRETAINLIST\n"); System.out.println(retainlist); } }

collectionsarraylist