array to string comma separated javascript

var colors = ["red", "blue", "green"];
var colorsCSV = colors.join(","); //"red,blue,green"

var fruits = ["Banana", "Orange", "Apple", "Mango"];

var energy = fruits.join();
 

//comma separated string into array
var colorsString="red,green,blue";
var colorsArray=colorsString.split(","); //split colorsString into array;
//console.log(colorsArray); ["red", "green", "blue"]