Convert a List of String to a comma separated String in Java

Given a List of String, the task is to convert the List to a comma separated String in Java. 

Examples:

Input: List<String> = ["Geeks", "ForGeeks", "GeeksForGeeks"]
Output: "Geeks, For, Geeks"

Input: List<String> = ["G", "e", "e", "k", "s"]
Output: "G, e, e, k, s"

Approach: This can be achieved with the help of join() method of String as follows.

1. Get the List of String.
2. Form a comma separated String from the List of String using join() method by passing comma ‘, ‘ and the list as parameters.
3. Print the String.

Below is the implementation of the above approach: 

Program:

Java

// Java program to convert List of String
// to comma separated String

import java.util.*;

public class GFG {
    public static void main(String args[])
    {

        // Get the List of String
        List<String>
            list = new ArrayList<>(
                Arrays
                    .asList("Geeks",
                            "ForGeeks",
                            "GeeksForGeeks"));

        // Print the List of String
        System.out.println("List of String: " + list);

        // Convert the List of String to String
        String string = String.join(",", list);

        // Print the comma separated String
        System.out.println("Comma separated String: "
                           + string);
    }
}

Output

List of String: [Geeks, ForGeeks, GeeksForGeeks]
Comma separated String: Geeks,ForGeeks,GeeksForGeeks