TypeScript · Junior · Question 74 of 75

What type does a function parameter with a default value get?

function paginate(page = 1) { /* ... */ }

✓Correct answer: It's inferred from the default (number) and becomes optional for callers
2any
3It's required and must be annotated

Explanation

Callers may omit the argument or pass undefined; inside the function page is always a number.

Further reading

TS Handbook: More on Functions ↗

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