Default check a checkbox html

Question

I am trying to get a checkbox checked by default, but everything I have tried doesn't seem to work. I don't know if it has to do with the PHP that is in the code.

function show_subscription_checkbox ($id='0') {
    global $sg_subscribe;
    sg_subscribe_start();

    if ( $sg_subscribe->checkbox_shown ) return $id;
    if ( !$email = $sg_subscribe->current_viewer_subscription_status() ) :
        $checked_status = ( !empty($_COOKIE['subscribe_checkbox_'.COOKIEHASH]) && 'checked' == $_COOKIE['subscribe_checkbox_'.COOKIEHASH] ) ? true : false;
    ?>   
<p <?php if ($sg_subscribe->clear_both) echo 'style="clear: both;" '; ?>class="subscribe-to-comments">
        <input type="checkbox" name="subscribe" id="subscribe" value="subscribe" style="width: auto;" <?php if ( $checked_status ) echo 'checked="checked" '; ?>/>

        <label for="subscribe"><?php echo $sg_subscribe->not_subscribed_text; ?></label>
        </p>

This is a wordpress plugin that allows you to subscribe to blog comments.

I have tried

echo 'checked=\"checked\" ';
echo 'checked="checked" ' ;
echo 'checked> ';

The plugin author states that you used to be able to default check the checkbox but not anymore.

Answer 1

Since this is showing up in google for "default checked checkbox", I figured I'd answer it. Alpay was right: The correct way to ensure that a checkbox is checked by default is like so (followed by an example of one that is not checked):

<input type="checkbox" name="vehicle" value="Car" checked> I have a car    
<input type="checkbox" name="vehicle" value="Bike"> I have a bike

Answer was found on w3schools. The author of the original question was having trouble with his PHP code, which is not at all related to the question title.

Answer 2

In HTML, if you want a checkbox to be checked by default, see the following;

<input type="checkbox" name="name1" value="uc"> This checkbox is unchecked <br>
<input type="checkbox" name="name2" value="c" checked> This checkbox is checked<br>

So, you might consider changing

<?php if ( $checked_status ) echo 'checked="checked" '; ?>

to

<?php if ( $checked_status ) echo 'checked'; ?>