[JS] 배경색바꾸기

  <script type="text/javascript">
  
  
  var btns=document.querySelectorAll("button");
  for (var i = 0; i < btns.length; i++) {
	/* btns[i].onclick=function(){
		alert("dd");
	} */
	btns[i].onmouseover=function(){
		console.log("mouseover");
		this.style.backgroundColor="blue";
	};
	btns[i].onmouseout=function(){
		console.log("mouseout");
		this.style.backgroundColor="red";
	};
  }
  </script>