redirect to 404 page instead of Fatal error: Uncaught ArgumentCountError: Too few arguments to function

I made an MVC framework for training, and I get this error and I’m not sure what is wrong with my function.

when I open link like this : http://mvctrav.com/posts/show/6 it show me the post but when deleting the id like this http://mvctrav.com/posts/show/ it shows me the error

My error looks like this:

Fatal error: Uncaught ArgumentCountError: Too few arguments to function Posts::show(), 0 passed in C:xampphtdocstravapplibrariesCore.php on line 51 and exactly 1 expected in C:xampphtdocstravappcontrollersPosts.php:124 Stack trace: #0 C:xampphtdocstravapplibrariesCore.php(51): Posts->show() #1 C:xampphtdocstravpublicindex.php(4): Core->__construct() #2 {main} thrown in C:xampphtdocstravappcontrollersPosts.php on line 124

and my function is :

 public function show($id)
  {
    $post = $this->postModel->getPostById($id);
    $user = $this->userModel->getUserById($post->user_id);

    $data = [
      'post' => $post,
      'user' => $user
    ];

    $this->view('posts/show', $data);
  }

this is my Core class:

<?php
class Core
{
    protected $currentController = 'Pages';
    protected $currentMethod = 'index';
    protected $params = [];

    public function __construct()
    {
        //print_r($this->getUrl());

        $url = $this->getUrl();

        // Look in controllers for first value
        if (file_exists('../app/controllers/' . ucwords($url[0]) . '.php')) {
            // If exists, set as controller
            $this->currentController = ucwords($url[0]);
            // Unset 0 Index
            unset($url[0]);
        }

        // Require the controller
        require_once '../app/controllers/' . $this->currentController . '.php';

        // Instantiate controller class
        $this->currentController = new $this->currentController;

        // Check for second part of url
        if (isset($url[1])) {
            // Check to see if method exists in controller
            if (method_exists($this->currentController, $url[1])) {
                $this->currentMethod = $url[1];
                // Unset 1 index
                unset($url[1]);
            }
        }

        // Get params
        $this->params = $url ? array_values($url) : [];

        // Call a callback with array of params
        call_user_func_array([$this->currentController, $this->currentMethod], $this->params);
    }

    public function getUrl()
    {
        $url = isset($_GET['url']) ? $_GET['url'] : "/";
        $url = filter_var(trim($url, "/"), FILTER_SANITIZE_URL);
        $url = explode('/', $url);
        return $url;
    }
}

my problem is: link http://mvctrav.com/posts/show to be not found or redirecting to specific page instead of showing the error Thank you for trying to help!

Answer

I think you need to edit show() function to be like this:

public function show($id = null)
  {
    $post = $this->postModel->getPostById($id);
    $user = $this->userModel->getUserById($post->user_id);

    $data = [
      'post' => $post,
      'user' => $user
    ];
    if ($user !== false && null !== $id) {
      $this->view('posts/show', $data);
    } else {
      header('Location:'.'404.php');
    }
  }