学习目的
判定是否输入性别,主要考察isset()函数的使用
代码
form.php修改:
<?php
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<style type="text/css" title="text/css" media="all">
label{font-weight: bold; color: #300ACC;}
</style>
<body>
<!--Script 2.1 -form.html-->
<form action="handle_form.php" method="post">
<fieldset>
<legend>Enter your information in the form below:</legend>
<p><label>Name:<input type="text" name="name" class="name" /></label></p>
<p><label>Email Adress: <input type="text" name="email" class="email" /></label></p>
<p><label>Gender:</label><input type="radio" name="gender" value="M" />Male<input type="radio" name="gender" value="F" />Female</p>
<p><label>Age:<select>
<option value="0-29">Under 30</option>
<option value="30-60">Between 30 and 60</option>
<option value="60+">Over 60</option>
</select></label></p>
<p><label>Comments: <textarea name="comments" rows="3" cols="40"></textarea></label></p>
</fieldset>
<p align="center"><input type="submit" name="submit" value="Submit My Information" /></p>
</form>
</body>
</html>
handle_form.php修改:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<?php #Script 2.3 - handle_form.php #2
$name = $_REQUEST['name'];
$email = $_REQUEST['email'];
$comments = $_REQUEST['comments'];
if(isset($_REQUEST['gender']))
{
$gender = $_REQUEST['gender'];
}else{
$gender = NULL;
}
echo "<p>Thank you, <b>$name</b>,for the following comments:<br/>
<tt>$comments</tt></p>
<p>We reply to you at <i>$email</i></p>";
if($gender == 'M'){
echo '<p><b>Good Day, Sir!</b></p>';
}else if($gender == 'F'){
echo '<p><b>Good Day, Madam!</b></p>';
}else{
echo '<p><b>You forget to enter your gender!</b></p>';
}
?>
</body>
</html>
结果
知识点总结
isset()用于检查一个变量是否被设置,如果var具有不同于NULL,包括0、false或空字符串,则isset(var)条件为真,否则为假。
isset()函数只能测试一个变量是否有值(包括 0, FALSE,或者一个空字符串,但不能是NULL); 而empty()函数检查一个变量是否具有空值:空字符串、0 、NULL 或FALSE,当$var = FALSE、0、”“时,print_r(empty(
$var
))为0。