부록 : 코드의 힘 - 채팅 기능 추가 2017-11-15 01:24:41 소스코드 변경사항 See the Pen <a data-cke-saved-href='https://codepen.io/egoing/pen/YExXOz/' href='https://codepen.io/egoing/pen/YExXOz/'>add chat service</a> by egoing (<a data-cke-saved-href='https://codepen.io/egoing' href='https://codepen.io/egoing'>@egoing</a>) on <a data-cke-saved-href='https://codepen.io' href='https://codepen.io'>CodePen</a>.