方法重寫是子類提供父類已定義方法的具體實現(xiàn)，通過保持相同名稱和參數(shù)改變行為。 ①方法重寫使代碼更靈活，例如Shape基類的area()方法可被Circle和Square子類重寫以實現(xiàn)各自計算方式；②重寫要求子類方法與父類同名、同返回類型、同參數(shù)，Python無需特殊關(guān)鍵字，Java/C#用@Override/override標(biāo)註；③適用於繼承體系中子類需不同行為時，避免對final/sealed方法或不相關(guān)邏輯使用；④注意點包括勿改簽名致誤成重載、忘記調(diào)用父類方法、私有方法不可重寫及語言差異問題。

Method overriding is when a subclass provides a specific implementation for a method that's already defined in its parent class. The main point is that the child class can change how the method behaves while keeping the same name and parameters, which allows for more flexible and reusable code.

Why method overriding matters

Overriding methods makes your code more adaptable. For example, you might have a base class called Shape with a method area() . If you create subclasses like Circle and Square , each one can override area() to calculate it in a way that makes sense for that particular shape.

This helps keep your code organized — you define what each class should do in a general way at the top level, then fill in the details where they make the most sense.

How to override a method

Here's the basic idea:

• The method in the child class must have the same name, return type, and parameters as the parent method.
• You don't need any special keyword in some languages (like Python), just re-declare the method. In Java or C#, you often use keywords like @Override or override to make it clear.

For instance, if you have a class Animal with a method makeSound() , and a subclass Dog that overrides it, calling makeSound() on a Dog instance will use the version from Dog , not Animal .

When to use it (and when not to)

You'll usually want to override methods when you're working with inheritance and expect subclasses to behave differently than the parent. It's especially useful in things like event handlers, frameworks, or anything plugin-based.

But there are times to avoid it:

• If the parent method is marked as final or sealed , overriding won't work.
• Don't override just to add unrelated behavior — that can confuse others reading your code.
• If the method signature doesn't match exactly, you're not overriding — you're overloading or hiding, which can lead to bugs.

A few gotchas to watch for

Some common issues pop up when people start overriding methods:

• Accidentally changing the method signature and ending up with an overloaded method instead of an overridden one.
• Forgetting to call the parent method when you meant to extend it rather than completely replace it — in that case, use super() or equivalent.
• Using private methods in parent classes — those can't be overridden because they aren't visible to subclasses.

It's also worth noting that not all languages handle overriding the same way. So always check how your specific language works — Python is pretty forgiving, while Java and C# are stricter about matching signatures.

基本上就這些.

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