Java program converts ArrayList to String, String to ArrayList

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In this example, we will learn how to convert ArrayList to String and String to ArrayList in Java.

To understand this example, you should understand the followingJava ProgrammingTopic:

• Java ArrayList class

• Java string

Example1Convert ArrayList to string

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

Output Result

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

In the above example, we created an ArrayList named languages. Note this line,

languages.toString();

Here, the toString() method converts the ArrayList to a string. The entire ArrayList is converted to a single string.

NoteWe can also convert the ArrayList to a string array. For more information, please visitJava ArrayList to Array conversion.

Example2Convert ArrayList to string using join()

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

Output Result

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

In the above example, we used the join() method of the String class to convert the ArrayList to a string. For more information, please visitJava String join().

Example3Convert 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 a string to an array
　　　　String[] arr = str.split(",");
　　　　//Create an ArrayList from a string
　　　　ArrayList<String> languages = new ArrayList<>(Arrays.asList(arr));
　　　　System.out.println("ArrayList: ",　+　languages);
　　}
}

Output Result

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

In the above example, we created a string named str. We have used the split() method to convert the given string to an array. For more information on splitting strings, please visitJava String split().

Note expression

Arrays.asList(arr)

The asList() method converts a string array to an arraylist.

Java Examples Comprehensive