<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
 
<form action="welcome.php" method="post">
名字: <input type="text" name="fname">
年龄: <input type="text" name="age">
<input type="submit" value="提交">
</form>
 
</body>
</html>
欢迎<?php echo $_POST["fname"]; ?>!<br>
你的年龄是 <?php echo $_POST["age"]; ?>  岁。
<?php
$q = isset($_GET['q'])? htmlspecialchars($_GET['q']) : '';
if($q) {
    if($q =='RUNOOB') {
        echo '菜鸟教程<br>http://www.runoob.com';
    } else if($q =='GOOGLE') {
        echo 'Google 搜索<br>http://www.google.com';
    } else if($q =='TAOBAO') {
        echo '淘宝<br>http://www.taobao.com';
    }
} else {
    ?>
<form action="" method="get"> 
    <select name="q">
    <option value="">选择一个站点:</option>
    <option value="RUNOOB">Runoob</option>
    <option value="GOOGLE">Google</option>
    <option value="TAOBAO">Taobao</option>
    </select>
    <input type="submit" value="提交">
    </form>
<?php
}
?>

<?php
$q = isset($_POST['q'])? $_POST['q'] : '';
if(is_array($q)) {
    $sites = array(
        'RUNOOB' => '菜鸟教程: http://www.runoob.com',
        'GOOGLE' => 'Google 搜索: http://www.google.com',
        'TAOBAO' => '淘宝: http://www.taobao.com',
    );
    foreach($q as $val) {
        // PHP_EOL 为常量，用于换行
        echo $sites[$val] . PHP_EOL;
    }
    
} else {
    ?>
<form action="" method="post"> 
    <select multiple="multiple" name="q[]">
    <option value="">选择一个站点:</option>
    <option value="RUNOOB">Runoob</option>
    <option value="GOOGLE">Google</option>
    <option value="TAOBAO">Taobao</option>
    </select>
    <input type="submit" value="提交">
    </form>
<?php
}
?>

<?php
$q = isset($_GET['q'])? htmlspecialchars($_GET['q']) : '';
if($q) {
    if($q =='RUNOOB') {
        echo '菜鸟教程<br>http://www.runoob.com';
    } else if($q =='GOOGLE') {
        echo 'Google 搜索<br>http://www.google.com';
    } else if($q =='TAOBAO') {
        echo '淘宝<br>http://www.taobao.com';
    }
} else {
    ?><form action="" method="get">
    <input type="radio" name="q" value="RUNOOB" />Runoob
    <input type="radio" name="q" value="GOOGLE" />Google
    <input type="radio" name="q" value="TAOBAO" />Taobao
    <input type="submit" value="提交">
</form>
<?php
}
?>

<?php
$q = isset($_POST['q'])? $_POST['q'] : '';
if(is_array($q)) {
    $sites = array(
            'RUNOOB' => '菜鸟教程: http://www.runoob.com',
            'GOOGLE' => 'Google 搜索: http://www.google.com',
            'TAOBAO' => '淘宝: http://www.taobao.com',
    );
    foreach($q as $val) {
        // PHP_EOL 为常量，用于换行
        echo $sites[$val] . PHP_EOL;
    }
      
} else {
?><form action="" method="post"> 
    <input type="checkbox" name="q[]" value="RUNOOB"> Runoob<br> 
    <input type="checkbox" name="q[]" value="GOOGLE"> Google<br> 
    <input type="checkbox" name="q[]" value="TAOBAO"> Taobao<br>
    <input type="submit" value="提交">
</form>
<?php
}
?>