js join()


```typeconsole.log(elements.join());// expected output: "Fire,Air,Water"console.log(elements.join(''));// expected output: "FireAirWater"console.log(elements.join('-'));// expected output: "Fire-Air-Water"```


> [Array.prototype.join()](https://developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Global_Objects/Array/join)





