{"id":1255,"date":"2022-02-26T06:57:45","date_gmt":"2022-02-26T06:57:45","guid":{"rendered":"https:\/\/mdr.foobrdigital.com\/?p=1255"},"modified":"2022-02-26T06:57:45","modified_gmt":"2022-02-26T06:57:45","slug":"arraylist-class","status":"publish","type":"post","link":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/2022\/02\/26\/arraylist-class\/","title":{"rendered":"\u00a0ArrayList Class"},"content":{"rendered":"\n

In this tutorial, we will learn about the ArrayList class in Java. We will learn about different operations and methods of the arraylist with the help of examples.<\/p>\n\n\n\n

The ArrayList<\/code> class of the Java collections framework provides the functionality of resizable-arrays<\/strong>.<\/p>\n\n\n\n

It implements the List<\/code> interface.<\/p>\n\n\n\n

\"The
Java ArrayList Implementation<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

Java ArrayList Vs Array<\/h2>\n\n\n\n

In Java, we need to declare the size of an array before we can use it. Once the size of an array is declared, it’s hard to change it.<\/p>\n\n\n\n

To handle this issue, we can use the ArrayList<\/code> class. It allows us to create resizable arrays.<\/p>\n\n\n\n

Unlike arrays, arraylists can automatically adjust its capacity when we add or remove elements from it. Hence, arraylists are also known as dynamic arrays<\/strong>.<\/p>\n\n\n\n

\n\n\n\n

Creating an ArrayList<\/h2>\n\n\n\n

Before using ArrayList<\/code>, we need to import the java.util.ArrayList<\/code> package first. Here is how we can create arraylists in Java:<\/p>\n\n\n\n

ArrayList<Type> arrayList= new ArrayList<>();<\/code><\/pre>\n\n\n\n
Here, Type<\/var> indicates the type of an arraylist. For example,<\/p>\n\n\n\n
\/\/ create Integer type arraylist\nArrayList<Integer> arrayList = new ArrayList<>();\n\n\/\/ create String type arraylist\nArrayList<String> arrayList = new ArrayList<>();<\/code><\/pre>\n\n\n\n
In the above program, we have used Integer<\/code> not int. It is because we cannot use primitive types while creating an arraylist. Instead, we have to use the corresponding wrapper classes.<\/p>\n\n\n\n
Here,\u00a0Integer<\/code>\u00a0is the corresponding wrapper class of\u00a0int<\/code>.<\/p>\n\n\n\n
\n\n\n\n
Example: Create ArrayList in Java<\/h3>\n\n\n\n
import java.util.ArrayList;\n\nclass Main {\n  public static void main(String[] args){\n\n    \/\/ create ArrayList\n    ArrayList<String> languages = new ArrayList<>();\n\n    \/\/ Add elements to ArrayList\n    languages.add(\"Java\");\n    languages.add(\"Python\");\n    languages.add(\"Swift\");\n    System.out.println(\"ArrayList: \" + languages);\n  }\n}<\/code><\/pre>\n\n\n\n
Output<\/strong><\/p>\n\n\n\n
ArrayList: [Java, Python, Swift]<\/samp><\/code><\/pre>\n\n\n\n
In the above example, we have created an ArrayList<\/code> named languages<\/var>.<\/p>\n\n\n\n
Here, we have used the add()<\/code> method to add elements to the arraylist. We will learn more about the add()<\/code> method later in this tutorial.<\/p>\n\n\n\n
\n\n\n\n
Basic Operations on ArrayList<\/h2>\n\n\n\n
The ArrayList<\/code> class provides various methods to perform different operations on arraylists. We will look at some commonly used arraylist operations in this tutorial:<\/p>\n\n\n\n