
We can add any number of null elements in ArrayList. We want to store null elements on the list. Look at the below figure to understand better how ArrayList grows its capacity internally.Īfter adding new elements, ArrayList's size: 8ģ. ("After adding new elements, ArrayList's size: " +size) Therefore, when we add a new element to the list, its capacity is automatically grown by 50%. Since the initial capacity of array list is full. Create an array list with an initial capacity of 6.
Arraylist java code#
Program source code 2: package com.arraylisttest Let’s take an example program based on the growable nature of ArrayList.

Arraylist java series#
Sometimes, this series of elements can be 5, or sometimes, it can be 3 or 8. Suppose we have a series of elements in a program that we need to handle on a dynamic basis. The size of ArrayList is growable in nature. Original insertion array list order: Īfter adding duplicate element, ArrayList insertion orderĢ. Call iterator() method to iterate over the elements of the array list. ("After adding duplicate element, ArrayList insertion order ") Adding a duplicate element at position 2 and end of the list. ("Original insertion array list order: " +al) Create an ArrayList with an initial capacity of 10.Īl.add("A") // Adding element at index 0.Īl.add("B") // Adding element at index 1.Īl.add("C") // Adding element at index 2.Īl.add("D") // Adding element at index 3. Program source code 1: package arrayListProgram Let’s take an example program where we will use ArrayList to add duplicate elements in the list.

Since Java ArrayList class allows duplicate elements, we can add duplicate elements to the list. We want to add duplicate elements to the list. An ArrayList can be used in Java Application whenġ. That is, when to use ArrayList in Java application.

Now, we will understand realtime use of ArrayList in Java with example program. The old array of the collection will be gone in the garbage collection. When the underlying array is fixed, ArrayList class automatically creates a new array with a larger size or capacity and copies all the existing elements to the new array before adding the new elements. The ArrayList class automatically manages the size of the array when we add an element to the array list.
