1. Introduction

In Java, converting an ArrayList to a String representation is a common task. This conversion is often required when we need to print, log, or store the ArrayList elements as a String. In this post, we will explore how to convert an ArrayList to a String in Java using the toString() method and the String.join() method.

2. Program Steps

1. Create an ArrayList and add some elements to it.

2. Convert the ArrayList to a String using the toString() method and print the result.

3. Convert the ArrayList to a String using the String.join() method and print the result.

3. Code Program

import java.util.ArrayList;

public class ArrayListToString {

    public static void main(String[] args) {

        // Step 1: Create an ArrayList and add some elements to it
        ArrayList<String> fruitList = new ArrayList<>();
        fruitList.add("Apple");
        fruitList.add("Banana");
        fruitList.add("Cherry");

        // Step 2: Convert the ArrayList to a String using the toString() method
        String resultUsingToString = fruitList.toString();
        System.out.println("String using toString(): " + resultUsingToString);

        // Step 3: Convert the ArrayList to a String using the String.join() method
        String resultUsingJoin = String.join(", ", fruitList);
        System.out.println("String using join(): " + resultUsingJoin);
    }
}

Output:

String using toString(): [Apple, Banana, Cherry]
String using join(): Apple, Banana, Cherry

4. Step By Step Explanation

Step 1: We create an ArrayList named fruitList and add three elements ("Apple", "Banana", and "Cherry") to it.

Step 2: The toString() method of the ArrayList class is used to convert fruitList to a String. The toString() method returns a string representation of the ArrayList, including square brackets. The resulting String is printed to the console.

Step 3: The String.join() method is another way to convert an ArrayList to a String. It concatenates the ArrayList elements with a specified delimiter (in this case, a comma followed by a space). The String resulting from String.join() does not include square brackets and is printed to the console.