内容为空效果图为：
填写内容效果图：
下面是验证程序的代码：
<!doctype html>
<html>
<head>
<meta http-equiv="conent-type" content="text/html" charset="utf-8"/>
<style>
.red{
color:red;
}
</style>
</head>
<body>
<?php
function test_input($data){
$data=trim($data);
$data=stripslashes($data);
$data=htmlspecialchars($data);
return $data;
}
?>
<?php
$name=$email=$web=$comment=$gender="";
$nameerr=$emailerr=$weberr=$commenterr=$gendererr="";
if($_server['request_method']=="post"){
if(empty($_post['name'])){
$nameerr="必填名字";
}else{
$name=test_input($_post['name']);
}
if(empty($_post['email'])){
$emailerr="必填邮件";
}else{
$email=test_input($_post['email']);
}
if(empty($_post['web'])){
$weberr="必填网址";
}else{
$web=test_input($_post['web']);
}
if(empty($_post['comment'])){
$commenterr="必填备注";
}else{
$comment=test_input($_post['comment']);
}
if(empty($_post['gender'])){
$gendererr="必填备注";
}else{
$gender=test_input($_post['gender']);
}
}
?>
<h1>表单验证</h1>
<span class="red">*必填字段</span>
<form method="post" action="<?php echo htmlspecialchars($_server['php_self']);?>">
名字：<input type="text" name="name"/><span class="red"><?php echo "*".$nameerr;?></span>
<br/>
e-mail：<input type="text" name="email"/><span class="red"><?php echo "*".$emailerr;?></span>
<br/>
网址：<input type="text" name="web"/><span class="red"><?php echo "*".$weberr;?></span>
<br/>
备注：<textarea rows="10" cols="40" name="comment"></textarea><span class="red"><?php echo "*".$commenterr;?></span>
<br/>
性别：<input type="radio" name="gender" value="男"/>男<input type="radio" name="gender" value="女"/>女<span class="red"><?php echo "*".$gendererr;?></span>
<br/>
<input type="submit" value="提交验证"/>
</form>
<?php
echo "名字".$name;
echo "<br/>";
echo "e-mail：".$email;
echo "<br/>";
echo "网址：".$web;
echo "<br/>";
echo "备注：".$comment;
echo "<br/>";
echo "性别：".$gender;
echo "<br/>";
?>
</body>
</html>
以上就是php表单验证内容是否为空的实现代码 的内容。