👀 Views: 1801 💬 Answers: 1 📅 Created: 2025-06-14

typescript class inheritance method-override TypeScript

I'm experiencing an scenario with TypeScript class inheritance where a method in a subclass is returning 'undefined' instead of the expected value. I have two classes: a base class `Animal`, which has a method `speak`, and a derived class `Dog` that overrides this method. However, when I call the `speak` method on an instance of `Dog`, it seems to lose the context and returns 'undefined'. Here’s my base class definition: ```typescript class Animal { speak() { return 'Animal speaks'; } } ``` And my subclass looks like this: ```typescript class Dog extends Animal { speak() { const bark = () => { return 'Woof!'; }; return bark(); } } ``` When I create an instance of `Dog` and call `speak`, I expect it to return 'Woof!', but instead, I get 'undefined'. Here's how I am calling it: ```typescript const dog = new Dog(); console.log(dog.speak()); // Outputs: undefined ``` I've tried using `this` inside the `bark` function, thinking it could help maintain the context, but I'm still working with the same scenario. I also attempted to explicitly return the value from `bark` directly, but it seems that the arrow function may be the root of the question. Can anyone point out what I'm missing or if there's a better way to handle this situation in TypeScript? I'm using TypeScript 4.4.4. Any insights would be greatly appreciated!