I found one question regarding accessing object properties with using array literals and I was confused to see it working

const obj = {
  "1": "a",
  1: "b",
  [1]: "c",
  [2]: "k"
}
console.log(obj[1]) // c
console.log(obj[[1]]) //c

Can someone explain how this is working ?

I tried checking documentation but it wasn’t much helpful to get accurate answer