Ивор Барханский

<?php

class SomeClass
{
    private string $title = '';
    private string $content = '';
    private array $error = [];

    public function create(): void
    {
        if (empty($this->error)) {
            $this->add();
        }
        echo $this->getStatus();
    }

    private function add(): void
    {
        $query = "insert into posts set title = :title, content = :content, created = now()";
        $stmt = $this->conn->prepare($query);
        $stmt->bindParam(":title", $this->title);
        $stmt->bindParam(":content", $this->content);
        if (!$stmt->execute()) {
            $this->error[] = 'Запись в базу не прошла!';
        }
    }

    public function setTitle(string $string): void
    {
        if (empty($string)) {
            $this->error[] = 'Поле title не заполнено!';
        } elseif (strlen($string) <= 5) {
            $this->error[] = 'Поле title меньше 5 символов!';
        } else {
            $this->title = htmlspecialchars(strip_tags($string));
        }
    }

    public function setContent(string $string): void
    {
        if (empty($string)) {
            $this->error[] = 'Поле content не заполнено!';
        } else {
            $this->content = htmlspecialchars(strip_tags($string));
        }
    }

    private function getStatus(): string
    {
        if (empty($this->error)) {
            return '<div class="alert alert-success">Успешно!</div>';
        }
        $string = '';
        foreach ($this->error as $error) {
            $string .= "<li>$error</li>";
        }
        return "<div class=\"alert alert-danger\"><ol>$string</ol></div>";
    }
}

...
if (isset($_GET['title']) && isset($_GET['text'])) {
    $c = new SomeClass();
    $c->setTitle($_GET['title']);
    $c->setContent($_GET['text']);
    $c->create;
}
...

select `id` from table_1 where `id` not in (select distinct `UID` from table_2)

if (!isset($_GET['reloaded'])) {
  while(1) {
    sleep(5);
    if(time() > strtotime($date_end)) {
      header('Location:currentpage.php?reloaded=1');
      exit;
    }
  }
}

function php_func(){
echo "Stay Safe";
}

function clickMe(){
var result ="<?php php_func(); ?>"
document.write(result);
}

$array = [1, -20, 'tango', 'whiskey',];
/* echo $array[0]; // 1
 * echo $array[1]; // -20
 * echo $array[2]; // tango
 * echo $array[3]; // whiskey
*/

$array = ['foo' => 'bar', 'baz' => 27,]
/* echo $array[0]; // bar
 * echo $array[1]; // 27
 * echo $array['foo']; // bar
 * echo $array['baz']; // 27
*/