Java Program to Convert the ArrayList into a string and vice versa

Example 1: Convert the Arraylist into a String

 import java.util.ArrayList; class Main { public static void main(String[] args) { ArrayList<String> languages= new ArrayList<>(); // Add elements in the array list languages.add("Java"); languages.add("Python"); languages.add("JavaScript"); System.out.println("ArrayList: " + languages); // convert the arraylist into a string String arraylist = languages.toString(); System.out.println("String: " + arraylist); } }

Output

 ArrayList: [Java, Python, JavaScript] String: [Java, Python, JavaScript]

In the above example, we have created an arraylist named languages. Notice the line,

 languages.toString();

Here, the toString() method converts arraylist into a string. The entire arraylist is converted as a single string.

Note: We can also convert the arraylist into a string array. To learn more, visit Java ArrayList to Array Conversion.

Example 2: Convert ArrayList to String Using join()

 import java.util.ArrayList; class Main { public static void main(String[] args) { ArrayList<String> languages= new ArrayList<>(); // Add elements in the array list languages.add("Java"); languages.add("Python"); languages.add("JavaScript"); System.out.println("ArrayList: " + languages); // convert the arraylist into a string String arraylist = String.join(", ", languages); System.out.println("String: " + arraylist); } }

Output

 ArrayList: [Java, Python, JavaScript] String: Java, Python, JavaScript

In the above example, we have used the join() method of the String class to convert the arraylist into a string. To learn more, visit Java String join().

Example 3: Convert a String to ArrayList

 import java.util.ArrayList; import java.util.Arrays; class Main { public static void main(String[] args) { // create a string String str = "Java, JavaScript, Python"; System.out.println("String: " + str); // convert the string into an array String[] arr = str.split(","); // create an arraylist from the string ArrayList<String> languages = new ArrayList<>(Arrays.asList(arr)); System.out.println("ArrayList: " + languages); } }

Output

 String: Java, JavaScript, Python ArrayList: [Java, JavaScript, Python]

In the above example, we have created a string named str. We have used the split() method to convert the given string into an array. To learn more about splitting a string, visit Java String split().

Notice the expression,

 Arrays.asList(arr)

The asList() method converts the string array into an arraylist.