在JavaScript中如何定义及输出螺旋矩阵

(function() {
 var map = (function() {
 function map(n) {
 this.map = [], this.row = 0, this.col = -1, this.dir = 0, this.n = n;
 // 建立个二维数组
 for (var i = 0; i < this.n; i++) { this.map.push([]); }
 // 定义移动的顺序为 右，下，左，上
 var order = [this.right, this.bottom, this.left, this.up];
 i = 0;
 do {
 // 能移动则更新数字，否则更改方向
 order[this.dir % 4].call(this) ? i++ : this.dir++;
 // 赋值
 this.map[this.row][this.col] = i;
 } while (i < n * n);
 }
 map.prototype = {
 print: function() { for (var i = 0; i < this.n; i++) { console.log(this.map[i].join(' ')) } },
 // 向该方向移动
 left: function() { return this.move(this.row, this.col - 1); },
 right: function() { return this.move(this.row, this.col + 1); },
 up: function() { return this.move(this.row - 1, this.col); },
 bottom: function() { return this.move(this.row + 1, this.col); },
 // 如果坐标在范围内，并且目标没有值，条件满足则更新坐标
 move: function(row, col) {
 return (0 <= row && row < this.n) && (0 <= col && col < this.n) && !this.map[row][col] && (this.row = row, this.col = col, true);
 },
 };
 return map;
 })();
 new map(6).print();
})();