<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script>
var oddSum = function(n,fn){
var sum = 0
fn = fn || function(n){
return n
}
for(var i=0i<ni++){
if((i+1)&1==1){
for(var j=0j<i+1j++){
if((j+1)&1==1)
sum+=fn(j+1)
}
}
}
return sum
}
var factorial = function(n){
return n>1 ? n*factorial(n-1) :1
}
document.write('S=1+(1+3)+(1+3+5)+…+(1+3+5+…+19)'+oddSum(19))
document.write('<br>')
document.write('S=1!+ (1!+3! )+(1!+3!+5!)+…+(1!+3!+5!+…+19!)'+oddSum(19,function(n){ return factorial(n) }))
</script>
</head>
<body>
</body>
</html>
这样的有几种写法,一个就是发送请求给后台,传的数据是邮箱,然后获取用户名,域名,顶级域名,然后渲染到页面上,但是这得后台配合,第二个就是自己声明假的数据,就是一个数组,里面有多个对象,比如:<input type="text" placeholder="请输入邮箱">
<button>开始分析</button>
<div>
用户名:<span class="username"></span></br>
域名:<span class="domain"></span></br>
顶级域名:<span class="top-domain"></span>
</div>
<script type="text/javascript">
var arr = [{email:"xx@163.com",username:"zhangsan",domain:"hao123",topDomain:".com"},{email:"yy@qq.com",username:"lisi",domain:"baidu",topDomain:".com"},{email:"zz@msn.com",username:"wangwu",domain:"taobao",topDomain:".com"}]
var inp = document.getElementsByTagName("input")[0]
var btn = document.getElementsByTagName("button")[0]
var username = document.getElementsByClassName("username")[0]
var domain = document.getElementsByClassName("domain")[0]
var topDomain = document.getElementsByClassName("top-domain")[0]
btn.onclick = function() {
var val = inp.value
username.textContent = ""
domain.textContent = ""
topDomain.textContent = ""
for (var i=0i<arr.lengthi++) {
if (val == arr[i].email) {
username.textContent = arr[i].username
domain.textContent = arr[i].domain
topDomain.textContent = arr[i].topDomain
}
}
}
</script>