<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>扩展运算符应用</title>
</head>
<body>
<div>1</div>
<div>2</div>
<div>3</div>
<div>4</div>
</body>
<script>
/*利用扩展运算符将伪数组转成真数组*/
// var oDivs= document.getElementsByTagName('div');
// console.log(oDivs)
// console.log( oDivs instanceof Array) //判断是不是真数组
//
// let arr =[...oDivs];
// console.log(arr)
// console.log(arr instanceof Array)
let arrLike = {
"0" : 1,
"1": 3,
'2' :4,
"length" :3
}
//from 将伪数组转成数组并对数据进一步处理
const _arr = Array.from(arrLike,(item) =>{
return item*2
})
console.log(_arr)
</script>
</html>
运行结果
