javascript - 如何从对象数组中的嵌套数组中获取数组值的组合

Question

我有一个具有以下结构的对象数组:

 var varientSections = [
  {
    type: "frame",
    values: ["black", "white", "wood"]
  },
  {
    type: "finish",
    values: ["matte", "glossy"]
  }
];

我想获取数组值的组合并用它创建一个新列表。 现在我可以使用名为getCombination(varientSections) 的方法从嵌套数组值中检索组合。但是，我不知道如何创建具有以下结构的新列表:

var results = [
  {
    attributes: [
      {
        type: "frame",
        value: "black"
      },
      {
        type: "finish",
        value: "matte"
      }
    ]
  },
  {
    attributes: [
      {
        type: "frame",
        value: "black"
      },
      {
        type: "finish",
        value: "glossy"
      }
    ]
  },
  {
    attributes: [
      {
        type: "frame",
        value: "white"
      },
      {
        type: "finish",
        value: "matte"
      }
    ]
  },
  {
    attributes: [
      {
        type: "frame",
        value: "white"
      },
      {
        type: "finish",
        value: "glossy"
      }
    ]
  },
  {
    attributes: [
      {
        type: "frame",
        value: "wood"
      },
      {
        type: "finish",
        value: "matte"
      }
    ]
  },
  {
    attributes: [
      {
        type: "frame",
        value: "wood"
      },
      {
        type: "finish",
        value: "glossy"
      }
    ]
  }
];

下面是我的代码:

function getCombinations(arr) {
  if (arr.length === 0) {
    return [[]];
  }

  let [current, ...rest] = arr;
  let combinations = getCombinations(rest);

  var result = current.values.reduce(
    (accumulator, currentValue) => [
      ...accumulator,
      ...combinations.map(c => [currentValue, ...c])
    ],
    []
  );
  console.log("result is ");
  console.log(result);
  return result;
}

let varientCombinations = getCombinations(varientSections);
console.log(varientCombinations);

let updatedVarientDetails = [];
varientSections.forEach((varientSection, index) => {
  let type = varientSection.type;
  varientCombinations.forEach(combination => {
    let obj = [
      {
        type: type,
        value: combination[index]
      },
    ];
    updatedVarientDetails.push(obj);
  });
});

console.log(updatedVarientDetails);

Answer 1

您可以获得笛卡尔积，稍后再赋予它所需的样式。名称和值取自移交的对象。

该算法采用所有键/值对并对值有严格的看法，这意味着如果找到数组或对象，因此 w && typeof w === "object"，实际部分用于添加额外的键/值对。

例如一个有两个属性的小对象

{ a: 1, b: [2, 3] }

产量

[
    { a: 1, b: 2 },
    { a: 1, b: 3 }
]

更高级一点的对象，比如

{ a: 1, b: { c: { d: [2, 3], e: [4, 5] } } }

产生与给定相同的结构

[
    {
        a: 1,
        b: {
            c: { d: 2, e: 4 }
        }
    },
    {
        a: 1,
        b: {
            c: { d: 2, e: 5 }
        }
    },
    {
        a: 1,
        b: {
            c: { d: 3, e: 4 }
        }
    },
    {
        a: 1,
        b: {
            c: { d: 3, e: 5 }
        }
    }
]

这意味着，从任何找到的子对象中获取笛卡尔积并将其与实际值相结合。

const
    getCartesian = object => Object.entries(object).reduce(
        (r, [key, value]) => {
            let temp = [];
            r.forEach(s =>
                (Array.isArray(value) ? value : [value]).forEach(w =>
                    (w && typeof w === "object" ? getCartesian(w) : [w]).forEach(x =>
                        temp.push({ ...s, [key]: x })
                    )
                )
            );
            return temp;
        },
        [{}]
    ),
    data = [{ type: "frame", value: ["black", "white", "wood"] }, { type: "finish", value: ["matte", "glossy"] }],
    result = getCartesian(data)
        .map(o => ({ attributes: Object.assign([], o).map(({ ...o }) => o) }));

console.log(result);

console.log(getCartesian({ a: 1, b: { c: { d: [2, 3], e: [4, 5] } } }));

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