React Hooks

[klequis]

useReducer

• Alternate to useState
• Returns current state paired with dispatch method
• Preferable to useState for
  • complex logic with multiple sub-values
  • when next state depends on previous state
  • Allows you to pass dispatch down to components instead of callbacks

useCallback

• Returns a memorized callback
• Used to keep the ref of the function the same between renders unless a value in the dependency array changes.

useMemo

Returns a memorized value

That's all folks. It just saves you from recomputing something unless on of the values in the dependencies array changes. It is purely for performance.

useRef

• Holds a mutable value
• Often the value is a component like
• But it can also be used to keep around mutable values similar to how you would use fields in classes.

useLayoutEffect

Same as useEffect but fires synchronously after all DOM mutations. Not often used.