usePrevious

React state hook that returns the previous state as described in the React hooks FAQ

Usage

Live Editor

function Demo() {
  const [count, setCount] = useState(0);
  const prevCount = usePrevious(count);

  return (
    <div>
      <button onClick={() => setCount(count + 1)}>+</button>
      <button onClick={() => setCount(count - 1)}>-</button>
      <p>
        Now: {count}, before: {prevCount}
      </p>
    </div>
  );
};

Result

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API

usePrevious

Returns

T | undefined: previous value

Arguments

Argument	Description	Type	DefaultValue
state	state value	T (Required)	-