𝗕𝗲𝗵𝗮𝘃𝗶𝗼𝗿𝗮𝗹 𝗗𝗲𝘀𝗶𝗴𝗻 𝗣𝗮𝘁𝘁𝗲𝗿𝗻𝘀 𝟮𝟬𝟮𝟲
You know how to build objects. You know how to organize them. Now you must learn how they talk to each other.
Behavioral patterns solve the hardest question in software: How should objects collaborate?
Poor design leads to:
- Tightly coupled objects that break easily.
- Scattered state management.
- Massive conditional blocks that are hard to test.
- Chaotic event handling.
Senior developers use behavioral patterns to manage communication. Here are the most important ones you need for production.
𝗦𝘁𝗿𝗮𝘁𝗲𝗴𝘆 Use this when you have multiple ways to perform a task. Instead of a giant if-else block for different payment methods, create separate classes for each. This makes your code easy to extend.
𝗢𝗯𝘀𝗲𝗿𝘃𝗲𝗿 Use this for event-driven systems. When one object changes, all its dependents get notified automatically. Think of a stock ticker or a social media notification.
𝗖𝗼𝗺𝗺𝗮𝗻𝗱 Turn a request into a standalone object. This is how you build undo/redo features or task queues. Each action knows how to execute and reverse itself.
𝗦𝘁𝗮𝘁𝗲 Use this to manage complex workflows. Instead of checking status variables everywhere, make each state a class. This works perfectly for order processing or traffic lights.
𝗧𝗲𝗺𝗽𝗹𝗮𝘁𝗲 𝗠𝗲𝘁𝗵𝗼𝗱 Define the skeleton of an algorithm in a base class. Let subclasses fill in the specific steps. This reduces code duplication in data processing pipelines.
𝗖𝗵𝗮𝗶𝗻 𝗼𝗳 𝗥𝗲𝘀𝗽𝗼𝗻𝘀𝗶𝗯𝗶𝗹𝗶𝘁𝘆 Pass a request through a chain of handlers. Each handler decides if it can solve the problem or if it should pass it to the next person. This is common in middleware and support ticket systems.
𝗜𝘁𝗲𝗿𝗮𝘁𝗼𝗿 Access elements in a collection without showing how the collection works. This hides the internal structure of your data.
𝗠𝗲𝗱𝗶𝗮𝘁𝗼𝗿 Centralize communication. Instead of objects talking to everyone, they talk to one coordinator. This prevents a mess of connections.
𝗠𝗲𝗺𝗲𝗻𝘁𝗼 Capture an object's state so you can restore it later. Use this for snapshots and rollbacks.
𝗩𝗶𝘀𝗶𝘁𝗼𝗿 Add new operations to a stable structure without changing the objects themselves. This is useful for reporting or complex file systems.
𝗜𝗻𝘁𝗲𝗿𝗽𝗿𝗲𝘁𝗲𝗿 Build a mini-language for your app. Use this for rule engines or custom search queries.
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