Imagine an e-commerce app that handles payments via PayPal and Stripe. Without a pattern, your checkout code might look like this:
Provides a substitute or placeholder for another object to control access to it. 3. Behavioral Patterns dive into design patterns pdf github
"This book is for your personal use only. Please don't share it with any third parties except your family members. If you’d like to share the book with a friend or colleague, buy and send them a new copy." Imagine an e-commerce app that handles payments via