Java Program to Get the Size of the Collection

In this article, we will understand how to get the size of the collection. The Collection is a framework that provides architecture to store and manipulate the group of objects. Java Collections can achieve all the operations that you perform on a data such as searching, sorting, insertion, manipulation, and deletion.

Below is a demonstration of the same −

Suppose our input is −

Input list: [100, 180, 250, 300]

The desired output would be −

The size of the list = 4

Algorithm

Step 1 - START
Step 2 - Declare a list namely input_list.
Step 3 - Define the values.
Step 4 - Using the function size(), we get the size of the input_list.
Step 5 - Display the result
Step 6 - Stop

Example 1

Here, we bind all the operations together under the ‘main’ function.

import java.util.*;
public class Demo {
   public static void main(String[] args){
      List<Integer> input_list = new ArrayList<Integer>();
      input_list.add(100);
      input_list.add(180);
      input_list.add(250);
      input_list.add(300);
      System.out.println("The list is defined as: " + input_list);
      int list_size = input_list.size();
      System.out.println("\nThe size of the list = " + list_size);
   }
}

Output

The list is defined as: [100, 180, 250, 300]

The size of the list = 4

Example 2

Here, we encapsulate the operations into functions exhibiting object oriented programming.

import java.util.*;
public class Demo {
   static void print_size(List<Integer> input_list){
      int list_size = input_list.size();
      System.out.println("\nThe size of the list = " + list_size);
   }
   public static void main(String[] args){
      List<Integer> input_list = new ArrayList<Integer>();
      input_list.add(100);
      input_list.add(180);
      input_list.add(250);
      input_list.add(300);
      System.out.println("The list is defined as: " + input_list);
      print_size(input_list);
   }
}

Output

The list is defined as: [100, 180, 250, 300]

The size of the list = 4