PHP: \Exception or Exception inside a namespace - php

Question

I am trying to handle some errors in my api. However I tried some so many ways to execute what it's needed to it done?
In the code i used Exception, \Exception, another class extending to Exception, "use \Exception".
None of these options works.
What i need to do execute the block catch?
//Piece of source in the begin of file
namespace Business\Notifiers\Webhook;
use \Exception;
class MyException extends \Exception {}
//Piece of source from my class
try{
$products = $payment->getProducts();
if(count($products) == 0)
return;
$flight_id = $products[0]->flight_id;
$this->message = 'Sir, we have a new request: ';
$products = null; //Chagind it to null to force an error..
foreach($products as $product){
$this->appendAttachment(array(
'color' => '#432789',
'text' =>
"*Name:* $product->name $product->last_name \n" .
"*Total Paid:* R\$$product->price\n",
'mrkdwn_in' => ['text', 'pretext']
));
}
} catch(Exception $e){
$this->message = "A exception occurred ";
} catch(\Exception $e){
$this->message = "A exception occurred e";
} catch(MyException $e){
$this->message = "A exception occurred";
}

Answer 1

The accepted answer above give the real cause of the issue, but did not answer the topic
If in case someone is interested and is looking for
what is the difference between Exception and \Exception inside a namespace?
Still valid against PHP 7.3.5:
\Exception: Refer to Exception in root namespace
Exception: Refer to Exception in current namespace
PHP does not fall back to root namespace, if the class cannot be found in current name space, it emits an error.
<?php
namespace Business;
try {
throw new Exception("X"); // Uncaught Error: Class 'Business\Exception' not found
} catch (Exception $e) {
echo "Exception: " . $e->getMessage();
}
<?php
namespace Business;
class Exception extends \Exception {} // means \Business\Exception extends \Exception
$a = new Exception('hi'); // $a is an object of class \Business\Exception
$b = new \Exception('hi'); // $b is an object of class \Exception

Answer 2

First of all, you need to understand the difference between an exception and an error:
http://php.net/manual/en/language.exceptions.php
http://php.net/manual/en/ref.errorfunc.php
Trying to foreach over a null value will not yield an exception, but trigger an error. You can use an error handler to wrap an error in an exception, as such:
<?php
function handle ($code, $message)
{
throw new \Exception($message, $code);
}
set_error_handler('handle');
// now this will fail
try {
$foo = null;
foreach ($foo as $bar) {
}
} catch(\Exception $e) {
echo $e->getMessage();
}
However in your code, you can simply check if $products is null and if so, throw an exception:
if (!$products) {
throw new \Exception('Could not find any products')
}
foreach($products as $product) { ...