sku排列算法，库存类展示(规格，型号，颜色等)

常用于电商类项目（超浅显层面）

例如一种商品有三种规格：颜色，尺寸，种类

颜色又分为：[红，黄，蓝]

尺寸：[A,B]

种类：[1,2,3]

可以结合为多种排列

如：[‘红’，A,1],[‘黄’，A,1],....等，可以用到sku排列算法：

　　摘抄的代码，原地址给忘了，

let arr = [
		    [1, 2, 3],
		    ['红', '黄', '蓝'],
		    ['A', 'B']
		];
		 
		function cartesianProductOf() {
		    return Array.prototype.reduce.call(arguments, (fristItem, secondItem) => {
		        var ret = [];
		        fristItem.forEach(function(fristItem) {
		            secondItem.forEach(function(secondItem) {
		                ret.push(fristItem.concat([secondItem]));
		            });
		        });
		        return ret;
		    }, [[]]);
		}
		 
		let allArr =cartesianProductOf(...arr )
		console.log(allArr)

　　返回结果：

 1 (18) [Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3), Array(3)]
 2 0: (3) [1, "红", "A"]
 3 1: (3) [1, "红", "B"]
 4 2: (3) [1, "黄", "A"]
 5 3: (3) [1, "黄", "B"]
 6 4: (3) [1, "蓝", "A"]
 7 5: (3) [1, "蓝", "B"]
 8 6: (3) [2, "红", "A"]
 9 7: (3) [2, "红", "B"]
10 8: (3) [2, "黄", "A"]
11 9: (3) [2, "黄", "B"]
12 10: (3) [2, "蓝", "A"]
13 11: (3) [2, "蓝", "B"]
14 12: (3) [3, "红", "A"]
15 13: (3) [3, "红", "B"]
16 14: (3) [3, "黄", "A"]
17 15: (3) [3, "黄", "B"]
18 16: (3) [3, "蓝", "A"]
19 17: (3) [3, "蓝", "B"]
20 length: 18
21 __proto__: Array(0)

也可以简化一下：

 1 <script type="text/javascript">
 2         let arr = [
 3             [1, 2, 3],
 4             ['红', '黄', '蓝'],
 5             ['A', 'B']
 6         ];
 7         fn = (a, b) => [].concat(...a.map(d => b.map(e => [].concat(d, e))));
 8         specification = (a, b, ...c) => (b ? specification(fn(a, b), ...c) : a)
 9         let output = specification(...arr)
10         console.log(output)
11     </script>

结果和上面相同，记下来慢慢学习规整