State on the Chain

Your first contract: a CRUD notes registry

Lesson 2 of 5

Structs, mappings and events are the whole toolkit. Build create, read, update and delete for notes that only their author can touch.

What you'll learn

Declare Solidity state with a struct, a mapping and an auto-incrementing id
Implement create, read, update and delete and explain why delete only zeroes storage
Emit events and explain why front-ends read events instead of scanning storage

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