Java ArrayList size() Method with Example

Arraylist.size() – Java ArrayList size() Method with Example

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Arraylist.size(): In the previous article we have discussed about Java ArrayList isempty() Method with Example

In this article we are going to see the use Java ArrayList  size() method along with suitable examples.

Java ArrayList size() Method with Example

size():

Size of an arraylist: This java.util.ArrayList.size() method is used to know the number of elements present in the arraylist.

It returns the size of the ArrayList

Syntax:

arrayListName.size()

Where,

  • arrayListName refers to the name of your ArrayList.

Let’s see different examples to understand it more clearly.

Method-1: Java ArrayList size() Method – Example with String Type ArrayList

Approach:

  • Create a new ArrayList of type String.
  • Add string elements into the ArrayList using the add() method.
  • Display the ArrayList elements.
  • Then find the size of the arrayList using size() method
  • Print the size of the ArrayList.

Program:

import java.util.*;
public class Main
{
    public static void main(String[] args)
    {
        // Create an ArrayList of string datatype
        ArrayList<String> arr = new ArrayList<String>();
        // Adding some elements to the ArrayList
        arr.add("c");
        arr.add("c++");
        arr.add("java");
        arr.add("python");
        arr.add("c#");
        // Prints the ArrayList elements
        System.out.println("The elements of ArrayList are: "+arr);
        // Prints the size of the  ArrayList
        System.out.println("The size of the ArrayList is: "+arr.size());
    }
}

Output:

The elements of ArrayList are: [c, c++, java, python, c#]
The size of the ArrayList is: 5

Method-2: Java ArrayList size() Method – Example with Integer Type ArrayList

Approach:

  • Create a new ArrayList of type String.
  • Add Integer elements into the ArrayList using the add() method.
  • Display the ArrayList elements.
  • Then find the size of the arrayList using size() method
  • Print the size of the ArrayList.

Program:

import java.util.*;
public class Main
{
    public static void main(String[] args)
    {
        // Create an ArrayList of Integer datatype
        ArrayList<Integer> arr = new ArrayList<Integer>();
        // Adding some elements to the ArrayList
        arr.add(10);
        arr.add(20);
        arr.add(30);
        arr.add(40);
        arr.add(50);
        arr.add(60);
        arr.add(70);
        // Prints the ArrayList elements
        System.out.println("The elements of ArrayList are: "+arr);
        // Prints the size of the  ArrayList
        System.out.println("The size of the ArrayList is: "+arr.size());
    }
}
Output:

The elements of ArrayList are: [10, 20, 30, 40, 50, 60, 70]
The size of the ArrayList is: 7

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