我工作的家庭作业，并已令人头大我的大脑试图找出如何做到以下几点：
在这一点上，我不得不由没有进入触发原来的错误，但是，一旦我测试不符合字母，数字或8个字符，我没有得到预期的响应的第二种情况。
下面是我写到目前为止以及HTML中的JS的例子：
任何帮助，将在很大程度上感谢！先感谢您！
window.onload = init;
function checkRegistration() {
var checkev = 0;
var uName = document.pageForm.userName.value;
var alphaNum = /^[a-z0-9]+$/i;
var password = document.pageForm.password.value;
if (uName == "") {
document.getElementById('userName').innerHTML = "A username is required.";
checkev=0;
} else if (uName.match != alphaNum)
document.getElementById('userName').innerHTML = "Username must contain at least one letter and one number, no special characters.";
{
document.getElementById('userName').innerHTML = "";
checkev++;
}
if (password == "") {
document.getElementById('password').innerHTML = "A password is required.";
checkev = 0;
} else if (password.lenth >= 8)
document.getElementById('password').innerHTML = "A password of at least 8 characters is required.";
else {
document.getElementById('password').innerHTML = "";
checkev++;
}<!DOCTYPE html>
<html lang="en-US">
<head>
<title>Invitation Page</title>
<link rel="stylesheet" type="text/css" href="css/main.css" />
<script src="js/registration.js"></script>
</head>
<form name="pageForm">
<form action="#">
<label for="userName">Username:</label>
<input type="text" name="userName" placeholder="Enter your Username" />
<span class="error" id="userName"></span><br><br>
<label for="Password">Password:
</label>
<input type="password" name="password" placeholder="Enter your Password" />
<span class="error" id="password"></span><br><br>
<input type="button" value="Submit" onclick="checkRegistration()">
</form>
</form>1个错字和1个逻辑问题。
尝试password.length < 8
<input type="text" name="userName" id="userName" placeholder="Enter your Username" />
<input type="password" name="password" id="password" placeholder="Enter your Password" />
你错过id属性，当你使用getElementById()和好运...
不要硬编码您的验证只需使用V4F
检查出更多的细节https://v4f.js.org
import {Field, Schema} from "v4f";
export Schema({
username: Field()
.alpha()
.min(1)
.required(),
password: Field()
.min(8)
.required()
});