Is it possible to use slice in React?

Question

React

Please answer the question)
Is it correct to use slice to change the state in react? I read on some resources that this mutates the state, but in theory it returns a new array without changing the original
one. Please tell me the correct answer)

Answer 1

The dock is written in Russian . Nothing is mutated.

Answer 2

You can use it, but do not forget that slice, that spread operator they make a copy of only a flat object (array).

const arr = [0, 1, [2,3]]
const newArr = arr. slice(0)
newArr[2][0] = 'new data'
console.log(arr[2][0]) // new data

If you need to avoid mutation for a deep object, then either JSON.stringify, JSON.parse, or cloneDeep from lodash is used. Or you can write an object traversal function yourself.
There are also specialized immutable(deprecated) or immerjs libraries.