<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
var phone = prompt('请输入手机号码：');
var res = isPhone(phone);
if (res) {
console.log('其是有效手机号码！');
} else {
console.log('其不是有效手机号码！');
}
function isPhone(phone) {
if (phone.length !== 11) {
return false;
}
if (isNaN(phone)) {
return false;
}
if (phone.charAt(0) !== '1') {
return false;
}
if (!'356789'.includes(phone.charAt(1))) {
return false;
}
return true;
}
</script>
</body>
</html>
