Will calling a set state function with the same value using hooks cause a rerender

Question

With the help of code can i know Will calling a set state function with the same value using hooks cause a rerender?

Answer 1

No, calling a setState function with the same value using React hooks does not cause a rerender, provided the value is shallowly equal to the current state. Here’s the precise explanation:

How It Works

React’s useState and useReducer hooks use shallow equality (Object.is) to compare the new state value with the current state value.

If the new value is identical to the current value (same primitive value or same object reference), React skips the rerender to optimize performance.

Examples

Primitive Values:

const [count, setCount] = useState(5);

setCount(5); // No rerender: 5 === 5 (same value)

setCount(6); // Rerenders: 5 !== 6

Objects (Reference Equality):

const [obj, setObj] = useState({ key: 'value' });

const sameObj = obj;

setObj(sameObj); // No rerender: same reference

setObj({ key: 'value' });