var arr = ['red', 'green', 'blue'];
console.log(arr.valueOf()); //['red', 'green', 'blue']
console.log(arr.toString()); //red,green,blue
console.log(arr.join(",")); //red,green,blue
var arr = ['red', 'green', 'blue'];
console.log(arr.valueOf()); //['red', 'green', 'blue']
console.log(arr.toString()); //red,green,blue
console.log(arr.join(",")); //red,green,blue