Why the output is showing undefined "submit" in php?

Question

Actually I was creating a simple form to send mail to my email ID. Here's my code:

<!doctype html>
<html>
    <body>
        <form>
            <input type='text' name='name'>
            <input type='email' name="email">
            <input type="number" name="mobile">
            <input type="text" name="message">
            <input type="submit" name='submit'>
        </form> 
    </body>
</html>

php code:

<?php
if($_POST['submit']!="")
{
 $cname = $_POST['name'];

 $email = $_POST['email'];
 $mob = $_POST['mobile'];
 $query = $_POST['message'];
 $subject="Enquiry";
 $message="Name : $cname \n  email : $email \n  Message : $query \n";
 $email_from = '<name@gmail.com.com>';
 $subject = "registration";
 $message = "You have received a new message from the user <b> $cname. </b> \n". "Here is the message:\n $message".
 $to = "name<name@gmail.com>";
 $headers = "From: $email_from \r\n";
 $headers.= "Reply-To: $email \r\n";
    if(mail($to, $subject, $message, $headers))
    {
     echo "<script>alert('Dear User, You Are Successfully Registered')</script>";
    }
}
?>

Note: In this question I have changed my actual email id with "name", in my actual code, the id is putten correctly. The error is in the first if statement that the 'submit' is undefined.

[What is the default form HTTP method?](https://stackoverflow.com/questions/2314401/what-is-the-default-form-http-method) - without specifying the method, it will be `$_GET` — Nigel Ren, Oct 11 '20 at 13:42

score 0 · Accepted Answer · answered Oct 11 '20 at 13:40

If you load the page, $_POST is empty and $_POST["submit"] is undefined. If you click the submit button, $_POST["submit"] is set. So, instead of checking if the content of $_POST["submit"] is an empty string, check if the variable is set:

if( isset($_POST["submit]) ){
   // Form submitted, continue
}

Also, you forgot to set the method in your form:

<form method="post">

Why the output is showing undefined "submit" in php?

1 Answers1