PHP获取单选按钮值问题求助：匿名选择表单失效

Hey there! Let's get your anonymous selection form working properly. I notice a couple of key issues in your code that are likely causing the problem—let's break them down and fix them step by step.

1. Missing HTML Form Wrapper #

Your radio buttons aren't wrapped inside a <form> element with the correct method, which means the form data won't be sent via POST to your PHP script. Without this, $_POST['anonym'] will never be set!

Corrected HTML Code #

<form method="post" action="">
  <input type="radio" name="anonym" value="ja" />Ja
  <input type="radio" name="anonym" value="nei" checked/>Nei
  <!-- Don't forget the submit button with the correct name! -->
  <button type="submit" name="snd_skjema">Submit</button>
</form>

2. PHP Code Improvements #

There are a couple of potential pitfalls in your PHP logic:

• You're using $id without ensuring it's defined—this will throw an error if $id hasn't been initialized elsewhere.
• It's good practice to add a fallback case in case the anonym value isn't set (even though you have a default checked radio, edge cases can happen).

Corrected PHP Code #

if (isset($_POST['snd_skjema'])) {
    // First, make sure $id is defined (replace with your actual user ID logic)
    $id = isset($_SESSION['user_id']) ? $_SESSION['user_id'] : null; // Example using session
    
    // Check if the 'anonym' value exists before using it
    if (isset($_POST['anonym'])) {
        if ($_POST['anonym'] == 'ja') {
            $anonym = $id; // Only assign if $id is valid
        } elseif ($_POST['anonym'] == 'nei') {
            $anonym = null;
        }
    } else {
        // Fallback in case no option was selected (though your default should prevent this)
        $anonym = null;
    }

    // Optional: Debug to see what values you're getting
    var_dump($_POST);
    var_dump($anonym);
}

Quick Debug Tip #

If it's still not working, add var_dump($_POST); right at the start of your PHP script. This will show you exactly what data is being sent from the form—if anonym isn't in the output, double-check your form's method and the radio button names.

内容的提问来源于stack exchange，提问作者Lowtexx