ساخت اندیس درون حافظه با جاوا اسکریپت — از صفر تا صد

1const skus = [
2  {
3    "productId": 1,
4    "colorId": 1,
5    "sku": "11-M"
6  },
7  {
8    "productId": 1,
9    "colorId": 1,
10    "sku": "11-L"
11  },
12  {
13    "productId": 1,
14    "colorId": 2,
15    "sku": "12-M"
16  },
17  {
18    "productId": 1,
19    "colorId": 2,
20    "sku": "12-L"
21  },
22  {
23    "productId": 2,
24    "colorId": 1,
25    "sku": "21-M"
26  },
27  {
28    "productId": 2,
29    "colorId": 1,
30    "sku": "21-L"
31  }
32];

1skus.find(s => productId === s.productId)

1const skus = [
2  {
3    "productId": 1,
4    "colorId": 1,
5    "sku": "11-M"
6  },
7  {
8    "productId": 1,
9    "colorId": 1,
10    "sku": "11-L"
11  },
12  {
13    "productId": 1,
14    "colorId": 2,
15    "sku": "12-M"
16  },
17  {
18    "productId": 1,
19    "colorId": 2,
20    "sku": "12-L"
21  },
22  {
23    "productId": 2,
24    "colorId": 1,
25    "sku": "21-M"
26  },
27  {
28    "productId": 2,
29    "colorId": 1,
30    "sku": "21-L"
31  }
32];

1const productIndex = indexByField(skus, “productId”);

1{
2  "1": [
3    {
4      "productId": 1,
5      "colorId": 1,
6      "sku": "11-M"
7    },
8    {
9      "productId": 1,
10      "colorId": 1,
11      "sku": "11-L"
12    },
13    {
14      "productId": 1,
15      "colorId": 2,
16      "sku": "12-M"
17    },
18    {
19      "productId": 1,
20      "colorId": 2,
21      "sku": "12-L"
22    }
23  ],
24  "2": [
25    {
26      "productId": 2,
27      "colorId": 1,
28      "sku": "21-M"
29    },
30    {
31      "productId": 2,
32      "colorId": 1,
33      "sku": "21-L"
34    }
35  ]
36}

1const mapObjectValues = (value, shouldMap, mapFn, ...args) => {
2  if (shouldMap(value)) {
3    return mapFn(value, ...args);
4  }
5  return {
6    ...Object.keys(value).reduce(
7      (acc, k) => ({
8        ...acc,
9        [k]: mapObjectValues(value[k], shouldMap, mapFn, ...args),
10      }),
11      {},
12    ),
13  };
14};

1const indexBy = (value, ...fields) => {	
2  if (fields.length === 0) {	
3    return value;	
4  }	
5  const [currentField, ...rest] = fields;	
6  const newValue = mapObjectValues(value, Array.isArray, indexByField, currentField);	
7  return indexBy(newValue, ...rest);	
8};	
9Array.prototype.indexBy = function(...fields) {	
10  return indexBy(this, ...fields);	
11};

1const productColorIndex = skus.indexBy(“productId”, "colorId");

1{
2  "1": {
3    "1": [
4      {
5        "productId": 1,
6        "colorId": 1,
7        "sku": "11-M"
8      },
9      {
10        "productId": 1,
11        "colorId": 1,
12        "sku": "11-L"
13      }
14    ],
15    "2": [
16      {
17        "productId": 1,
18        "colorId": 2,
19        "sku": "12-M"
20      },
21      {
22        "productId": 1,
23        "colorId": 2,
24        "sku": "12-L"
25      }
26    ]
27  },
28  "2": {
29    "1": [
30      {
31        "productId": 2,
32        "colorId": 1,
33        "sku": "21-M"
34      },
35      {
36        "productId": 2,
37        "colorId": 1,
38        "sku": "21-L"
39      }
40    ]
41  }
42}

1productColorIndex["1"]["2"];