Quiz · 3 questions

🪝 Functions — Where Most Beginner Pain Lives

Function types, overloads, arrow vs declared, this typing, contextual typing

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Quiz

01What does (e: Event) => void mean as a function type?

Hint

Compare this to a parameter typed : undefined, which would only allow explicit returns of undefined.

02When should you use a function overload signature?

Hint

If you can express the relationship between arguments and return with function f<T>(x: T): T extends string ? number : string, generics + conditional types is usually cleaner than overloads.

03What's the real difference between an arrow function and a function declaration?

Hint

Try setTimeout(this.handler, 1000) vs setTimeout(() => this.handler(), 1000). The first loses this; the second preserves it.

← PreviousContextual Typing: When TypeScript Reads Your Callsite 📐 Arrays & Tuples — Where Position Matters →Arrays: `T[]` and `Array<T>`

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