0
151
ViewsCreating an Array clone with spread operator, but it still has reference to original array
So I have these few lines of code:
console.log(...cells);
let testCells = [...cells];
testCells[index].shape = selectedShape;
testCells[index].player = player;
console.log(...cells);
The interesting thing is that it is console.log()ing back the following.
I don't quite get it, why does cells change? There is no other part of the code that could interfere with cells. Any tips?
·
Santiago Trujillo
1 answers
Answer question0
It looks like even though you're spreading all the objects into the new array, it is still a reference to the old objects. You can break the reference by using JSON.stringify and JSON.parse to avoid any old unintended relationships.
const cells = [
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
{shape: 0, player: 0},
];
console.log(...cells);
const breakRef = obj => JSON.parse(JSON.stringify(obj));
let testCells = breakRef(cells);
testCells[0].shape = 1;
testCells[0].player = 0;
console.log(...cells);
·
Santiago Trujillo
Report
Answer question