Display() function overriding

hi everyone . I am trying to execute a simple PHP statement e.g die(‘view.detail.php display Function’); in Display fucntion of Contacts/views/view.detail.php but it is not working .is there any other way to add display logic or Js . I am working for 2 months still fail to find out a way to execute custom PHP/JS code . even documentation is not good enough .any help would be appreciated .please

What are you trying to do here? Maybe you have display_error settings in the php.ini file. Also, check your log files.

So far I am just chceking out areas where custom code can or cannot work and understanding framework so that custom php/js may be implemented later on… so far i have not found anythinig for module level customization not even a single PHP die or JS console.log statement h

thank you for sharing .i have already gone through this but its not working as even for test purpose I have customized modules/Contacts/views/view.detail.php display() fucntion still no error no execution of code .
I dont know may be anything wrong with deprecation errors .I am testing on localhost xampp windowsNT .Already Checked Compatibility Matrix everything is oky still in case I turn on display_error it shows Return type of Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in C:\xampp\htdocs\lingua\vendor\symfony\http-foundation\Session\Attribute\AttributeBag.php on line 134

if I turn it off it shows no error and do not execute.