Validation and error handling

중급~30 분0/4 단계

Protect the ledger from bad input

Real users mistype, paste spaces, and leave fields empty. Production code treats that as expected behavior. A validation function either returns a clean transaction or throws a precise error. The submit handler catches it and shows a useful message.

Never silently turn invalid money into zero. Invalid is not empty, and empty is not zero.

안내

Create createTransaction(description, amount) and trim the description.

힌트: const cleanDescription = description.trim();

Reject a short description and non-positive or non-finite amount.

Wrap transaction creation in try/catch.

Show the error message in #form-error.

내 코드

html

5 줄

Validation and error handling

Protect the ledger from bad input

안내

내 코드

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