Create a Comma Separated List from an Array in JavaScript

Here are the different methods to create comma separated list from an Array

1. Array join() method

The Array join() method joins the elements of the array to form a string and returns the new string. The elements of the array will be separated by a specified separator.

let a = ["GFG1", "GFG2", "GFG3"];

function fun() {
    console.log("Comma Separates List: " + a.join(", "));
}
fun();

Comma Separates List: GFG1, GFG2, GFG3

• The code defines an array containing three elements: "GFG1", "GFG2", and "GFG3".
• The function uses a.join(", ") to create a comma-separated list of the array elements and logs it to the console.

2. Array toString() method

Array toString() method converts an array into a String and returns the new string. It returns a string that represents the values of the array, separated by a comma.

let a = ["GFG1", "GFG2", "GFG3"];
function fun() {
    console.log("Comma Separated List: " + a.toString());
}

fun();

Comma Separated List: GFG1,GFG2,GFG3

• The code defines an array with elements "GFG1", "GFG2", and "GFG3".
• The function uses the toString() method to convert the array into a string, with the elements separated by commas by default.

3. Using Array literals

Array literals is the list of expressions containing array elements separated with commas enclosed with square brackets. 

let a = ["GFG1", "GFG2", "GFG3"];

function fun() {
    console.log("Comma Separated List: " + a);
}

fun();

Comma Separated List: GFG1,GFG2,GFG3

• The code defines an array with elements "GFG1", "GFG2", and "GFG3" using an array literal.
• The function directly logs the array arr to the console. When an array is logged as a string, JavaScript automatically converts it to a comma-separated list.

4. Using Lodash _.join() method

Lodash _.join() method return the list of given array with "," separation.

// Requiring the lodash library 
let _ = require("lodash");
let a = [1, 2, 3, 4, 5, 6];

let newA = _.join(a);
console.log("After Join: " + newA);

Output

After Join: 1,2,3,4,5,6

• The code imports the lodash library using require("lodash"), enabling access to its utility functions.
• The _.join(array) function from Lodash is used to join the elements of the array into a string, with the default separator being a comma.

5. Using map() and join()

To create a comma-separated list from an array using map() and join(), first convert each array element to a string using map(String), then join these strings into a single string separated by commas using join(',').

const a = [1, 2, 3, 4, 5];
const comma = a.map(String).join(',');
console.log(comma); 

1,2,3,4,5

• The code uses map(String) to convert each element of the array arr into a string, and then join(',') joins these string elements with commas.
• The result is a comma-separated string "1,2,3,4,5", which is logged to the console.