```<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>箭头函数的应用</title>
<style type="text/css">
#ad{
width: 200px;
height: 200px;
background-color: blueviolet;
}
</style>
</head>
<body>
<div id="ad">
</div>
<script type="text/javascript">
let ad = document.querySelector('#ad')
// 实现点击一个div 2s后变成粉色的需求
ad.addEventListener('click',function(){
setTimeout(()=>{
// console.log(this)
this.style.background = 'pink'
},2000)
})
let arr = [1,6,9,43,54,2]
let arr2 = [
{
num:1
},
{
num:2
},
{
num:3
}
]
let result = arr.filter((item)=>{
if(item % 2 === 0){
return item
}
})
let result2 = arr2.filter(item => item.num % 2 === 0)
console.log(result2)
</script>
</body>
</html>
