dynamic - php keep dynamically generated radio button checked after submit -

i know there other topics covering this, read through them, tried solutions, , still running issues.

i have array, $gendervalues, loop through in order echo 2 radio buttons inside of form. form has other inputs validation. when user checks male or female, want radio button remain checked when try submit form fail meet other validation, rather having clear itself.

$gendervalues = ['male','female'];  function ending ($genderval) {          if (isset($_post['gender']) && ($_post['gender'] == $genderval)) {             $ending = " checked />";                 return $ending;         }         else{             $ending = "/>";             return $ending;          }     }      foreach($gendervalues $genderval){          echo "<label class='radio' for=" . $genderval . ">" . $genderval . "</label>         <input type='radio' name='gender' id=" . $genderval . " value=" . $genderval . ending($genderval);      } 

change line:

<input type='radio' name='gender' id=" . $genderval . " value=" . $genderval . ending($genderval); 

to this:

<input type='radio' name='gender' id=" . $genderval . " value='" . $genderval . "' " . ending($genderval);