x和y的位置是什么

Question

此数组中x和y的位置是什么：

var a = [ [1,2], [x], [3, [y]] ];

我对这里的语法有点困惑。
它会是：

a[1] = x and a[2][1] = y? 

或者引入一组新的方括号意味着我们改为：

a[1][0] = x and a[2][1][0] = y?

Answer 1

让我们一起发现;）

var a = [ [1,2], [x], [3,[y]]];

如果你逐行写出：

var a = [
  [1,2],   // new array with index 0 containing 1 and 2 => a[0][0] = 1 and a[0][1] = 2
  [x],     // new array with index 1 containing x => a[1][0] = x
  [3,[y]]  // new array with index 2 containing 3 and array containing y a[2][0] = 3 a[2][1][0] = y 
];

换句话说，x = a [1] [0]

Answer 2

var x = "x";
var y = "y";
var a = [ [1,2], [x], [3, [y]] ];

console.log(a[1][0]);
console.log(a[2][1][0]);