我决定通过测试来做一点测试，以查看该表单是否会检测到一个空的输入字段，并且它不起作用，我不知道问题出在哪里，我也不想写剩下的该项目的问题，如果这一件小事不起作用，那么这是代码，我已经看过它了，我认为我没有错过任何事情。
这是HTML：
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<form method="POST" action="myform.php">
<fieldset>
<legend>Personal Info</legend>
First name <input name="name" type="text">
Middle name <input name="middlename" type="text">
Surname <input name="lastname" type="text">
Age <input name="age" type="number">
Date of birth <input name="dob" type="date">
</fieldset>
<fieldset>
<legend>Regional & location info</legend>
Continent
<select>
<option value="europe">Europe</option>
<option value="americas">America</option>
<option value="africa">Africa</option>
<option value="asia">Asia</option>
<option value="australia">Australia</option>
<option value="eurasia">Eurasia</option>
</select>
Country <input type="text"> State <input type="text">
City <input type="text">
Street number <input type="number">
Street name <input type="text"> <br><br>
Suburb <input type="text"> Postcode <input type="number">
If none of these apply to your accommodations, enter a typed location here <input type="text">
</fieldset>
<fieldset>
<legend>Previous lifestyle accommodations</legend>
Previous &/or most recent job title <input name="job" type="text">
First time job seeker <input type="checkbox" name="check1" value="ftjb">
I'm a student <input type="checkbox" name="check2" value="ias">
Previous &/or most recent acedemic title <input name="school" type="text">
First time applying for a qualification <input type="checkbox" name="check3" value="ftafaq">
I have work experience <input type="checkbox" name="check4" value="ihwe">
</fieldset>
<fieldset>
<legend>Details of arrival</legend>
Reason for arrival of all parties <input name="reason" type="text">
Date of arrival <input name="arrival" type="date">
Amount of stay expectancy
<input type="checkbox" name="check3">Temporary
<input type="checkbox" name="check4">Longterm
</fieldset>
<fieldset>
<legend>Signiture</legend>
<input type="text">
</fieldset>
<input type="submit" value="Submit"><button type="reset">Reset</button>
</form>
</body>
</html>
这是到目前为止我在PHP中为表单所做的事情：
<?php
$nameInvalid = "";
$middleInvalid = "";
$surnameInvalid = "";
$ageInvalid = "";
$dobInvalid = "";
$countryInvalid = "";
$cityInvalid = "";
$strtInvalid = "";
$strnameInvalid = "";
$suburbInvalid = "";
$postcodeInvalid = "";
$jobInvalid = "";
$ftjsInvalid = "";
$iasInvalid = "";
$schoolInvalid = "";
$check1Invalid = "";
$check2Invalid = "";
$checl3Invalid = "";
$check4Invalid = "";
$reasonInvalid = "";
$arrivalInvalid = "";
if (isset($_POST['submit'])) {
if (empty($_POST["name"])) {
$nameInvalid = "Name is required";
}
}
?>
答案 0 :(得分：1)
请在按钮中添加 name =“ submit” 属性。
<input type="submit" value="Submit" name="submit">
并且还请在验证中添加回显，以打印验证消息，如下所示。
if (isset($_POST['submit'])) {
if (empty($_POST["name"])) {
echo $nameInvalid = "Name is required";
}
}
答案 1 :(得分：0)
HTML
如果表单不符合您的规则，您需要使用HTML5 validation来阻止发送表单。
摘自官方文档：
最简单使用的HTML5验证功能是required属性-如果要强制输入，则可以使用此属性标记元素。设置此属性后，当输入为空（输入也将被视为无效）时，表单将不会提交（并显示错误消息）。
根据您的情况，尝试将required标记添加到要测试的字段，例如name字段：
First name <input name="name" type="text" required>
要使其更加有趣，请添加一些CSS：
input:invalid {
border: 2px dashed red;
}
input:valid {
border: 2px solid black;
}
PHP
要验证PHP响应，您需要做的是以下操作：
if (!$_REQUEST["name"]) {
//If the name field is empty
die("Name is missing");
//Replace this with whatever logic fits your code
}
我们正在使用$_REQUEST，这意味着同时使用 $_POST和$_GET，但是如果您愿意，可以坚持使用$_POST 。我们正在使用if(!$val)进行验证，这是最简单的方法，但是有一些警告（见下文），您也可以使用if(empty($val))，但对于字符串，第一个很好。
摆脱在脚本开头定义为空的变量列表。相反，要查看设置数组 if 的值，该值不应为空，而是为空。例如：
# Repeat this structure for each form field you want
if (!$_REQUEST["name"]) {
//If the name field is empty
$empty_fields[] = "name";
//Fill the $empty_fields array with all the fields that are missing
}
# At the end, cycle thru the missing fields and tell the user
if(!empty($empty_fields)){
die("The following fields are missing: ".implode(", ", $empty_fields));
}
注意事项
使用if(!$val)是快捷方式，使用won't work是允许的值，例如“”（空格）或“ 0”（零），但是如果希望使用字符串值，则可以使用。< / p>
答案 2 :(得分：0)
使用此
<input type="submit" name="submit" value="Submit">
答案 3 :(得分：0)
我检查了代码及其正常工作。只需提供名称以提交按钮并在php页面中回显验证消息即可。
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<form method="POST" action="test1.php">
<fieldset>
<legend>Personal Info</legend>
First name <input name="name" type="text">
Middle name <input name="middlename" type="text"> Surname <input name="lastname" type="text"> Age <input name="age" type="number"> Date of birth <input name="dob" type="date">
</fieldset>
<fieldset>
<legend>Regional & location info</legend>
Continent
<select>
<option value="europe">Europe</option>
<option value="americas">America</option>
<option value="africa">Africa</option>
<option value="asia">Asia</option>
<option value="australia">Australia</option>
<option value="eurasia">Eurasia</option>
</select>
Country <input type="text"> State <input type="text"> City <input type="text">
Street number <input type="number"> Street name <input type="text"> <br><br>
Suburb <input type="text"> Postcode <input type="number"> If none of these apply to your accommodations, enter a typed location here <input type="text">
</fieldset>
<fieldset>
<legend>Previous lifestyle accommodations</legend>
Previous &/or most recent job title <input name="job" type="text"> First time job seeker <input type="checkbox" name="check1" value="ftjb"> I'm a student <input type="checkbox" name="check2" value="ias"> Previous &/or most recent acedemic title <input name="school" type="text"> First time applying for a qualification <input type="checkbox" name="check3" value="ftafaq"> I have work experience <input type="checkbox" name="check4" value="ihwe">
</fieldset>
<fieldset>
<legend>Details of arrival</legend>
Reason for arrival of all parties <input name="reason" type="text"> Date of arrival <input name="arrival" type="date"> Amount of stay expectancy <input type="checkbox" name="check3">Temporary <input type="checkbox" name="check4">Longterm
</fieldset>
<fieldset>
<legend>Signiture</legend>
<input type="text">
</fieldset>
<input type="submit" name="submit" value="Submit">
<button type="reset">Reset</button>
</form>
</body>
</html>
在php页面中显示回显消息。
<?php
$nameInvalid = "";
$middleInvalid = "";
$surnameInvalid = "";
$ageInvalid = "";
$dobInvalid = "";
$countryInvalid = "";
$cityInvalid = "";
$strtInvalid = "";
$strnameInvalid = "";
$suburbInvalid = "";
$postcodeInvalid = "";
$jobInvalid = "";
$ftjsInvalid = "";
$iasInvalid = "";
$schoolInvalid = "";
$check1Invalid = "";
$check2Invalid = "";
$checl3Invalid = "";
$check4Invalid = "";
$reasonInvalid = "";
$arrivalInvalid = "";
if (isset($_POST['submit']))
{
if (empty($_POST["name"]))
{
echo $nameInvalid = "Name is required";
}
}
?>
完成了。