Kuhifadhi Thamani Iliyochaguliwa kwenye Vitufe vya Redio Baada ya Kutuma kwenye PHP

Wacha tuandike kodi ambayo itahifadhi kitufe cha redio kilichowekwa alama baada ya kutuma fomu:

html<form action="" method="GET">
  <input type="radio" name="radio" value="1" <?php
    if (!empty($_GET['radio']) and $_GET['radio'] === '1') {
      echo 'checked';
    }
  ?>>
  <input type="radio" name="radio" value="2" <?php
    if (!empty($_GET['radio']) and $_GET['radio'] === '2') {
      echo 'checked';
    }
  ?>>
  <input type="radio" name="radio" value="3" <?php
    if (!empty($_GET['radio']) and $_GET['radio'] === '3') {
      echo 'checked';
    }
  ?>>
  <input type="submit">
</form>