如何将字符串附加到表单字段中的数据

Question

I have a form and I need a way of ensuring that only people with a particular email address can successfully signup. For example the only users allowed are from foo.com, so every email address should be like myemail@foo.com. Now I want the user to only have to enter the email user name and after the form is submitted I add the @foo.com using php. How would I go about implementing such a feature and if there is a better way to achieve the desired result where can I find such information . Thanks.

Answer 1

Easy, name the form field username for example. Name your submit button submit for example

then on form submit

if(isset($_POST['submit'])){
$username = $_POST['username'];
$username .= "@foo.com"   // jacksperro@foo.com

// rest of your code
}

On a note, I'd put a label after the input box saying '@foo.com' to let them know to only type their username

Answer 2

This is basic string concatenation.

$suffix = '@foo.com';
$username = 'test';
$email = $username . $suffix;

Answer 3

Try this, it should do what you need and more:

<?php 
if(isset($_POST['submit'])){

$user       = trim(htmlspecialchars($_POST['username'])); // a bit of security
$final_user = sprintf("%s@foo.com", $user);   // user@foo.com

echo $final_user;

}

?>