数组类型检测与转换
2020-03-16 本文已影响0人
小雪洁
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>类型检测与转换</title>
</head>
<body>
<div>hxj</div>
<div>ydc</div>
<script>
//类型检测
const array=[1,2,3];
console.log(Array.isArray(array));
//数组转字符串
/* console.log(array.toString());//1,2,3
console.log(array.join("-"));//1-2-3
console.log(String(array));//1,2,3
const str=array.join("-");
console.log(location.href+"?id="+str); */
//字符串转数组
const hxj="haoxuejie";
console.log(hxj.split());//["haoxuejie"]
console.log(hxj.split(""));// ["h", "a", "o", "x", "u", "e", "j", "i", "e"]
const hy="hxj,ydc";
console.log(hy.split(","));//["haoxuejie", "yangdingchuan"];
//Array.from(str)可以将字符串转成数组，因为字符串有length
console.log(Array.from(hy));//["h", "x", "j", ",", "y", "d", "c"]
const obj={
name:"hhh",
age:"30"
};
console.log(Array.from(obj));//[]
const o={
0:"hhh",
1:"30",
length:2
}
console.log(Array.from(o));//["hhh", "30"]
let divs=document.querySelectorAll("div");
console.log(divs);//NodeList(2) [div, div]
//Array.from()可以转换成数组，还可以对数组元素进行一定的处理
console.log(Array.from(divs));// [div, div]
Array.from(divs,function(item){
console.log(item.innerHTML);
item.style.background="pink";
return item;
});//hxj ydc
</script>
</body>
</html>
