with(): replacing one item in a copy

Useful to know

Array.prototype.with() returns a copy of the array with a replaced element of a specific index. For example, [4, 5, 6].with(1, 9) gives [4, 9, 6], with no change to the original. Negative indices . [1] are also allowed

The method is convenient when the state needs to be replaced with a new array. An index outside the scope leads to RangeError, so validate the position if it comes from a user's choice. It does not automatically add an arbitrary distant element and is not a substitute for an identifier search.