Form required fields

From the validation rules in the previous section, we see that the "Name", "E-mail" and "Gender" fields are required. These fields cannot be empty and must be filled in the HTML form.

Field Validation Rule

Name Required. Must contain letters and spaces.

E-mail required. Must contain a valid email address (including @ and .).

Website Optional. If optional, a valid URL must be included.

Comment Optional. Multi-line input field (text box).

Gender required. One must be selected.

In the previous section, all input fields were optional.

In the code below we have added some new variables: $nameErr, $emailErr, $genderErr and $websiteErr. These error variables hold the error message for the requested field. We also added an if else statement to each $_POST variable. This statement checks whether the $_POST variable is empty (via the PHP empty() function). If empty, the error message is stored in a different error variable. If not empty, the user input data is sent through the test_input() function:

PHP - Show error message

In the HTML form, we added a little script after each requested field. Appropriate error messages are generated if required (if the user attempts to submit the form without filling in required fields):

Example

"> Name:  *  

 E-mail:  *  

 Website:   

 Comment:  

 Gender: Female Male *  

  

    
   
PHP 验证实例
 
* 必需的字段
 
"> 姓名： *  

 电邮： *  

 网址：  

 评论： 

 性别： 女性 男性 *  

  
 您的输入："; echo $name; echo "
"; echo $email; echo "
"; echo $website; echo "
"; echo $comment; echo "
"; echo $gender; ?>  

PHP Validation Example

* Required fields

Name: *

Email: *

Website:

Comments:

Gender: Female Male

Your input: