how to show errors in JS Alert

Question

I have phtml form, whenever i get any error it shows a page like this

i want to show these type of errors like this

Answer 1

In your module controller

try {
            //Your program logic

    } catch (\Exception $e) {
            $this->messageManager->addErrorMessage("Your error message{$e->getMessage()}.");
            $this->_redirect('*/*/');
            return;
   }