padStart() 只针对字符串，padEnd向后补零 innerHtml创建dom元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<style>
li {
list-style: none;
color: aquamarine;
}
li:nth-child(2n) {
color: blueviolet;
}
</style>
<body>
<ul id="list"></ul>
</body>
<script type="text/javascript">
var perArr = []
// 遍历循环数组
for (var i = 0; i < 20; i++) {
console.log(i);
if (i % 2 == 0) {
perArr.push({
id: i,
name: "大幂幂",
age: i + 10
}, )
} else {
perArr.push({
id: i,
name: "蔡文姬",
age: i + 10
}, )
}
}
// 定义人员列表的html字符串
let htmlStr = ‘‘
// 用数据生成人员列表
perArr.forEach(item => {
htmlStr += `<li>${item.name}-${item.age}------${(item.id+1).toString().padStart(3, "0")}</li>`
console.log((item.id+1).toString().padEnd(3, "0"));
})
// 操作dom呈现界面
document.getElementById(‘list‘).innerHTML = htmlStr
</script>
</html>
原文：https://www.cnblogs.com/bigbang66/p/15122078.html