<pre>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<h3>判斷用戶名是否存在</h3>
<input type="text" name="username" id="username" value="">
<br>
<script src="ajax3.0-min.js"></script>
<script>
var username = document.getElementById('username');
username.onblur = function() {
var value = this.value;
Ajax().get('1.php?username=' + value, function(msg) {
console.log(msg);
if (msg == 1) {
alert('該用戶已經被註冊');
} else {
alert('該用戶還沒有被註冊');
}
})
}
</script>
</body>
</html>
</pre>
<?php
$username = $_GET['username'];
$arr = ['zhangsan','lisi','wangwu','zhaoliu'];
if (in_array($username,$arr)) {
echo 1;
} else {
echo 0;
}
