Array List example programs

1.  How to Iterate ArrayList using Java ListIterator Example  
2. Arraylist add element at specific index 
3. Sort ArrayList in descending order
4. Java program to insert an element to ArrayList using ListIterator Example  
5. How to sort arraylist of strings alphabetically java 
6. Java Program to Sort elements of Java ArrayList Example
7. Basic Java example program to replace an element at specified index arraylist
8. Search an element of Java ArrayList Example
9. Java Example Program to Remove element from specified index ArrayList

 import java.util.ArrayList;  
 import java.util.Collections;  
 import java.util.ListIterator;  
 import java.util.Comparator;  
 import java.util.Scanner;  
 public class CollectionLists {  
      public static void main(String [] args){  
           ArrayList<String> arrayList=new ArrayList<String>();  
           //adding elements to list  
           arrayList.add("A");  
           arrayList.add("B");  
           arrayList.add("C");  
           arrayList.add("D");  
           arrayList.add("E");  
           arrayList.add("F");  
           arrayList.add("G");  
           ListIterator<String> itr=arrayList.listIterator();  
           /*Use hasNext() and next()  
            * method to iterate through forward direction  
            */  
           System.out.println("Array List in forward direction");  
           while(itr.hasNext()){  
                System.out.println(itr.next());  
           }  
           /*Use hasPrevious() and previous()  
            * method to iterate through backward direction  
            */  
           System.out.println("Array List in backward direction");  
           while(itr.hasPrevious()){  
                System.out.println(itr.previous());  
           }  
           System.out.println("\n Adding element at specified index");  
           //adding element at specific index  
           arrayList.add(1,"a");  
           System.out.println(arrayList+"\n");  
           System.out.println("Sorting ArrayList in descending order");  
           //Sorting array in descending order  
           ArrayList<Integer> arrayList1=new ArrayList<Integer>();  
           //adding elements  
           arrayList1.add(1);  
           arrayList1.add(2);  
           arrayList1.add(3);  
           arrayList1.add(4);  
           arrayList1.add(5);  
           arrayList1.add(6);  
           arrayList1.add(7);  
           /*Using static comparator reverseOrder() method of  
            * collections utility class to get comparator object  
            */  
           Comparator<Integer> comparator=Collections.reverseOrder();  
           System.out.println("Before sorting "+arrayList1);  
           /*Using static void sort(List list,Comparator comp)  
            * method of collection class  
            */  
           Collections.sort(arrayList1,comparator);  
           System.out.println("After sorting "+arrayList1+"\n");  
      /*  
       * use Collections.sort(arrayList1) for Ascending order  
       */  
      System.out.println("Inserting element in Array List using ListIterator");  
      ListIterator<Integer> litr=arrayList1.listIterator();  
      System.out.println("Before inserting "+arrayList1);  
      litr.next(); //if this section is commented 9 will be printed first followed by 7  
      litr.add(9);  
      System.out.println("After sorting "+arrayList1+"\n");  
      System.out.println("Replace an element at specified index in Array List");  
      System.out.println("Before Replacing "+arrayList1);  
      arrayList1.set(1, 10);  
      System.out.println("After Replacing "+arrayList1+"\n" );  
      System.out.println("Search an element in ArrayList and get the index");  
      Scanner sc=new Scanner(System.in);  
      System.out.println("Type the number you want to search");  
      int x=sc.nextInt();  
      boolean isContains=arrayList1.contains(x);  
      int index=arrayList1.indexOf(x);  
      System.out.println("Does ArrayList contain "+x+"? "+isContains);  
      if(index==-1)  
           System.out.println("ArrayList does not contain "+x);  
      else  
           System.out.println("ArrayList does contain "+x+ " and it's index is "+index);  
      System.out.println("See for yourself "+arrayList1+"\n");  
      System.out.println("Remove an element from ArrayList based on index");  
      Object obj=arrayList1.remove(1);  
      System.out.println(obj+" has been removed from the list");  
      System.out.println("See for yourself "+arrayList1);  
      }  
 }  

Output:

Array List in forward direction
A
B
C
D
E
F
G
Array List in backward direction
G
F
E
D
C
B
A

 Adding element at specified index
[A, a, B, C, D, E, F, G]

Sorting ArrayList in descending order
Before sorting [1, 2, 3, 4, 5, 6, 7]
After sorting [7, 6, 5, 4, 3, 2, 1]

Inserting element in Array List using ListIterator
Before inserting [7, 6, 5, 4, 3, 2, 1]
After sorting [7, 9, 6, 5, 4, 3, 2, 1]

Replace an element at specified index in Array List
Before Replacing [7, 9, 6, 5, 4, 3, 2, 1]
After Replacing [7, 10, 6, 5, 4, 3, 2, 1]

Search an element in ArrayList and get the index
Type the number you want to search

3
Does ArrayList contain 3? true
ArrayList does contain 3 and it's index is 5
See for yourself [7, 10, 6, 5, 4, 3, 2, 1]

Remove an element from ArrayList based on index
10 has been removed from the list
See for yourself [7, 6, 5, 4, 3, 2, 1]