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Correction status：qualified
Teacher's comments：不错
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>JavaScript基础知识</title>
</head>
<body>
<h3>JS变量，语句，表达式</h3>
输入名字：<input type="text" name="name" id="input-a" onblur="log(this.value)">
<p id="js-p-a" style="color:red;font-weight:500;"></p>
</body>
</html>
<script>
//定义一个变量
var username = "xiaohu";
//定义一个命名函数
function reg() {
alert('hao');
}
//定义一个函数
function log($name) {
//一个简单if语句
if ($name == username) {
alert("登录成功");
document.getElementById("js-p-a").innerHTML = "欢迎你回来：" + $name;
} else {
alert("账户或密码错误");
document.getElementById("input-a").value = '';
document.getElementById("js-p-a").innerHTML = "账户或密码错误，请重新输入";
}
}
//一个匿名函数
window.onload = function() {
alert("别乱动");
};
//调用一个函数
window.onload = reg();
</script>点击 "运行实例" 按钮查看在线实例