How deeply does React in Depth cover stable value?

Explains reference identity through constants, functions, objects, useState setters, and useRef, without developing broader rendering internals.

Stable value

As explained in React in Depth

A stable value is a value whose identity remains unchanged across renders of a component.

A stable value keeps the same identity across component renders. It can be omitted from a hook dependency array when its reference is known never to change. This matters especially for functions and objects: identical behavior or structure does not guarantee identical identity. section 3.3.3

Common stable values include:

Constants defined outside a component or imported from another file. section 3.3.3
The setter returned by useState, whose function reference remains stable even when the state value changes. section 3.3.3
The object returned by useRef, whose identity remains stable while its current property remains dynamic. section 3.3.3

const [items, setItems] = useState(["Clean gutter", "Do dishes"]);
...
const onDelete = useCallback(
  (item) => setItems(     #1
    (list) => list.filter((i) => i !== item),
  ),
  []     #2
);

Shows useCallback omitting the stable useState setter from its dependency array. section 3.3.3

How React in Depth covers it

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Related concepts

useStateproduced by · useState is a React Hook that provides a function component with a state value and a function for updating it.
useRefproduced by · useRef is a React Hook that returns a persistent mutable object whose current property can hold a value across renders without causing re-rendering when changed.
dependency arrayuses · A dependency array is an array passed to a React effect or memoization Hook that specifies values whose changes trigger recomputation or rerunning.
valuekind of · A value is the content, quantity, information, or worth attributed to an entity, property, expression, or outcome.
useCallbackproduced by · useCallback is a React Hook that memoizes a function reference and reuses it across renders until its specified dependencies change.

This explainer was generated by Manning's knowledge graph from the text of React in Depth. The section links point to the parts of the book it draws on.