Preserving and Resetting State https://react.dev/learn/preserving-and-resetting-state https://react.dev/learn/preserving-and-resetting-state#the-ui-tree https://react.dev/learn/preserving-and-resetting-state#state-is-tied-to-a-position-in-the-tree pitfall 부분 To React, these two counters have the same “address”: the first child of the first child of the root. This is how React matches them up bet..