How to save checkbox selection mode based on user selection

Issue

I want the position of the checkbox to be saved when my form is submitted.

The problem with my code is that if the user enables or disables the checkbox; after submitting the form, the checkbox is marked and the user's choice is not taken into account.

My code:

<?php
function tets_checkBox() {
  if (isset($_POST['submit-post'])) {
    if (isset($_POST['email-post'])) {
      echo '<p class="alert alert-success">' . __('The checkbox is checked.') . '</p>';
    } else {
      echo '<p class="alert alert-danger">' . __('The checkbox is not checked.') . '</p>';
    }
    echo '<p class="alert alert-success">' . __('The settings for your account have been updated') . '</p>';        
  }
}
?>
  
<form method="post" action=" ">             
  <aside class="account_news">
    <label class="account_mainBtn">
      <input type="checkbox" name="email-post" checked>
    </label>
    <h3>Select.</h3>
  </aside>          
  <input type="submit" name="submit-post" value="<?php _e('Update settings'); ?>">          
</form>

---

Edit:

I have placed this form on the user account page and the user selects the check box to send or not send email by the site.

I want when the user selects the checkbox mode; Save the checkbox mode for that user so that after logging out and re-entering the account, the checkbox mode is still maintained for that user.

Solution

$checked_attr = "checked='checked'";
$flag = 0;

if ( isset( $_POST['submit-post'] ) ) {
    $flag = 1;
}

if ( 1 === $flag ) {
    $checked_attr = ''; 
    if ( isset( $_POST['email-post'] ) && ! empty( $_POST['email-post'] ) ) {
        $checked_attr = "checked='checked'";
    }
} 

tets_checkBox();
?>
<form method="POST" action="" >
                    
            <aside class="account_news">

                 <label class="account_mainBtn">
                     <input type="checkbox" name="email-post" <?php echo $checked_attr; ?>  >
                  </label>

                 <h3>Select.</h3>
            </aside>
                        
    <input type="submit" name="submit-post" value="<?php echo( 'Update settings' ); ?>">
                        
</form>

Answered By - Neha Bahadure