JS Practice — Built-in Objects

Interface — with Method

📖 Usage Example

interface Counter { count: number; increment(): void; decrement(): void }
const c = createCounter()
c.increment()
c.count   // → 1

Interface method signatures declare both the function shape and ensure objects provide implementations.

Interfaces with Methods

Interfaces can include method signatures. Implement an object that satisfies the interface.

Challenge: Implement createPrintable(label, value) returning an object with a toString() method.

createPrintable('Name', 'Alice').toString()  // → 'Name: Alice'

💡 Hints (1)