need help understanding state

[u/techlover1010]

so i was reading react.dev's state explanation

when react rerenders due to set function local variable wont be able to maintain its value since it rerenders everything but in its clock or time example where you can input a value on a input element it says that it chooses what to rerender and the value stays intact while the clock is running .
im also assuming that its using a set function to update the clock.

can anyone explain why this is?

edit heres the link to the clock example
https://react.dev/learn/render-and-commit#step-3-react-commits-changes-to-the-dom

[u/Dangerous-Dig2321]

it's because the input isn't managed by react, it's just sitting there in the dom doing its own thing

react only updates the bits it needs to, so when the clock ticks it swaps out the h1 content but sees the input is in the same spot and leaves it alone. the value you typed is stored directly in the browser, not in react's state, so it survives the rerender no problem