java arraylist count code example

Example 1: how to count the number of occurrences of an element in a arraylist in java

ArrayList<String> listName = new ArrayList<>();
int occurrences = Collections.frequency(listName, "element");

Example 2: get number of items in arraylist java

import java.util.ArrayList;

/*
 * Java Program to find the length of ArrayList. *
 */

public class ArrayListDemo{

  public static void main(String[] args) {
    System.out.println("Welcome to Java Program to find the length of array list");

    ArrayList<String> listOfBanks = new ArrayList<>();
    int size = listOfBanks.size();
    System.out.println("size of array list after creating: " + size);

    listOfBanks.add("Citibank");
    listOfBanks.add("Chase");
    listOfBanks.add("Bank of America");
    size = listOfBanks.size();

    System.out.println("length of ArrayList after adding elements: " + size);

    listOfBanks.clear();
    size = listOfBanks.size();
    System.out.println("size of ArrayList after clearing elements: " + size);
  }

}
Output
Welcome to Java Program to find length of array list
the size of array list after creating: 0
the length of ArrayList after adding elements: 3
the length of ArrayList after clearing elements: 0

Example 3: how to count the number of occurrences of an element in a arraylist in java

int occurrences = Collections.frequency(animals, "bat");