how to implement arraylist in java code example

Example 1: how to define an arraylist in java

ArrayList<Integer> integerArray = new ArrayList<Integer>();
ArrayList<String> integerArray = new ArrayList<String>();
ArrayList<Double> integerArray = new ArrayList<Double>();
//... keep replacing what is inside the <> with the appropriate
//data type

Example 2: arraylist in java

import java.util.ArrayList;
public class ArrayListExample
{
   public static void main(String[] args)
   {
      int num = 14;
      // declaring ArrayList with initial size num
      ArrayList<Integer> al = new ArrayList<Integer>(num);
      // append new element at the end of list
      for(int a = 1; a <= num; a++)
      {
         al.add(a);
      }
      System.out.println(al);
      // remove element at index 7
      al.remove(7);
      // print ArrayList after deletion
      System.out.println(al);
      // print elements one by one
      for(int a = 0; a < al.size(); a++)
      {
         System.out.print(al.get(a) + " ");
      }
   }
}

Example 3: arraylist in java

Size is dynamic
Only supports objects
not syncronized
array based class