Java Convert ArrayList to Comma Separated String

In this Java core tutorial we learn how to convert a java.util.ArrayList object to a comma separated String in Java programming language.

How to convert ArrayList to Comma Separated String in Java

In Java, with a given ArrayList object we can use the String.join(CharSequence delimiter, Iterable<? extends CharSequence> elements) static method to convert it to a comma separated String value as the following example Java code.

ConvertArrayListToCommaSeparatedStringExample1.java

import java.util.ArrayList;
import java.util.List;

public class ConvertArrayListToCommaSeparatedStringExample1 {
    public static void main(String... args) {
        List<String> arrayList = new ArrayList<>();

        arrayList.add("Java");
        arrayList.add("Kotlin");
        arrayList.add("Groovy");

        String commaSeparatedString = String.join(",", arrayList);

        System.out.println(commaSeparatedString);
    }
}