let arr = [1,2,3,4,5];
//arr[0], arr[2] swap
let temp = arr[0];
arr[0] = arr[2];
arr[2] = temp;
console.log(arr);
// [3,2,1,4,5]
let arr = [1,2,3,4,5];
//arr[0], arr[2] swap
[arr[2], arr[0]] = [arr[0], arr[2]];
console.log(arr);
// [3,2,1,4,5]
2개 뿐 아니라 n개 가능