Java Program to Iterate over an ArrayList

Java Program to Iterate over an ArrayList

In this example, we will learn to iterate over the elements of an arraylist in Java.

To understand this example, you should have the knowledge of the following Java programming topics:


Example 1: Iterate through ArrayList using for loop

import java.util.ArrayList;

class Main {
  public static void main(String[] args) {
    // Creating an array list
    ArrayList<String> languages = new ArrayList<>();
    languages.add("Java");
    languages.add("JavaScript");
    languages.add("Python");
    System.out.println("ArrayList: " + languages);

    // Using for loop
    System.out.println("Iterating over ArrayList using for loop: ");

    for(int i = 0; i < languages.size(); i++) {
      System.out.print(languages.get(i));
      System.out.print(", ");
    }
  }
}

Output

ArrayList: [Java, JavaScript, Python]
Iterating over ArrayList using for loop:
Java, JavaScript, Python,

In the above example, we have created an arraylist named languages. Here, we have used the for loop to access each element of the arraylist.


Example 2: Iterate through ArrayList using for-each loop

import java.util.ArrayList;

class Main {
  public static void main(String[] args) {
    // Creating an array list
    ArrayList<String> languages = new ArrayList<>();
    languages.add("Java");
    languages.add("JavaScript");
    languages.add("Python");
    System.out.println("ArrayList: " + languages);

        // Using forEach loop
    System.out.println("Iterating over ArrayList using for-each loop:");
    for(String language : languages) {
      System.out.print(language);
      System.out.print(", ");
    }
  }
}

Output

ArrayList: [Java, JavaScript, Python]
Iterating over ArrayList using for-each loop:
Java, JavaScript, Python,

Here, we have used the for-each loop to iterate over the ArrayList and print each element.


Example 3: Iterate over ArrayList using listIterator()

import java.util.ArrayList;
import java.util.ListIterator;

class Main {
  public static void main(String[] args) {
    // Creating an ArrayList
    ArrayList<Integer> numbers = new ArrayList<>();
    numbers.add(1);
    numbers.add(3);
    numbers.add(2);
    System.out.println("ArrayList: " + numbers);

    // Creating an instance of ListIterator
    ListIterator<Integer> iterate = numbers.listIterator();
    System.out.println("Iterating over ArrayList:");
    while(iterate.hasNext()) {
      System.out.print(iterate.next() + ", ");
    }
  }
}

Output

ArrayList: [1, 3, 2]
Iterating over ArrayList:
1, 3, 2,

In the above example, we have used the listIterator() method to iterate over the arraylist. Here,

  • hasNext() - returns true if there is next element in the arraylist
  • next() - returns the next element of the arraylist

Note: We can also use the ArrayList iterator() method and the ArrayList forEach() method to iterate over the arraylist.