Javascript基于多个值将数组与其他数组组合

Question

我有一个名为p的数组，它看起来像：

[
  {
    "Day": "Monday",
    "data": [
      "chest",
      "triceps",
      "shoulders"
    ]
  },
  {
    "Day": "Tuesday",
    "data": [
      "back",
      "biceps"
    ]
  },
  {
    "Day": "Thursday",
    "data": [
      "legs"
    ]
  }
]

我有另一个数组， program看起来像：（略读）

[
  {
    "target": "biceps",
    "data": [
      {
        "name": "barbell alternate biceps curl",
        "target": "biceps"
      },
      {
        "name": "barbell lying preacher curl",
        "target": "biceps"
      }
    ]
  },
  {
    "target": "triceps",
    "data": [
      {
        "name": "barbell incline reverse-grip press",
        "target": "triceps"
      },
      {
        "name": "barbell lying extension",
        "target": "triceps"
      }
    ]
  }
]

我需要程序来对p.data拥有的肌肉群进行分组。 它应该看起来像：

[
      {
        "target": "chest tricep shoulder",
        "data": [
          {
            "name": "chest exercise",
            "target": "chest"
          },

          {
            "name": "tricep exercise",
            "target": "tricep"
          },
          {
            "name": "shoulder exercise",
            "target": "shoulder"
          },
        ]
      },

      {
        "target": "back biceps",
        "data": [
          {
            "name": "back exercise",
            "target": "back"
          },

          {
            "name": "bicep exercise",
            "target": "bicep"
          },
        ]
      },
]

我试过这个（基于数组排序），但不是正确的尝试：

function mapOrder(array, order, property) {
  let ordered = [], unordered = [];

  // Iterate over each item in the supplied array of objects, separating ordered and unordered objects into their own arrays.
  array.forEach((item) => {
  if (order.indexOf(item[property]) === -1) {
      unordered.push(item);
  } else {
      ordered.push(item);
  }
  });

  // Sort the ordered array.
  ordered.sort((a, b) => {
  a = a[property], b = b[property];

  if (order.indexOf(a) < order.indexOf(b)) {
      return -1;
  } else {
      return 1;
  }
  });

  // Sort the unordered array.
  unordered.sort((a, b) => {
  a = a[property], b = b[property];

  if (a < b) {
      return -1;
  } else if (a > b) {
      return 1;
  } else {
      return 0;
  }
  });

  // Append the sorted, non-ordered array to the sorted, ordered array.
  ordered.push(...unordered);

  return ordered;
}

Answer 1

您可以使用以下实现：

 const programs = [ { target: "biceps", data: [ { name: "barbell alternate biceps curl", target: "biceps", }, { name: "barbell lying preacher curl", target: "biceps", }, ], }, { target: "triceps", data: [ { name: "barbell incline reverse-grip press", target: "triceps", }, { name: "barbell lying extension", target: "triceps", }, ], }, ]; // creates a Map which maps // muscle => Array of exercises const lookupTable = programs.reduce( (map, { target, data }) => (map.set(target, data), map), new Map() ); const p = [ { Day: "Monday", data: ["chest", "triceps", "shoulders"], }, { Day: "Tuesday", data: ["back", "biceps"], }, { Day: "Thursday", data: ["legs"], }, ]; // for each day map the respective exercises const result = p.map((day) => ({ // join together the muscles to a muscle group target: day.data.join(" "), // for each muscle get the respective exercises and put them in a list // if a muscle does not exist (as here in this limited example) set some default value (please adjust as you please) data: day.data.flatMap( (muscle) => lookupTable.get(muscle) || { name: `Muscle ${muscle} does not exist`, target: muscle, } ), })); console.log(JSON.stringify(result, null, 4));

 .as-console-wrapper { max-height: 100% !important; top: 0; }

首先，我使用Map创建一个查找表，该表将允许在O(1)中快速查找并将给定的肌肉映射到一组相应的练习，如下所示。

我为此使用reduce() ，但这不是必需的。 您可以事先创建Map并在数组的循环中手动添加数组。

Map(2) {
  'biceps' => [
    { name: 'barbell alternate biceps curl', target: 'biceps' },
    { name: 'barbell lying preacher curl', target: 'biceps' }
  ],
  'triceps' => [
    { name: 'barbell incline reverse-grip press', target: 'triceps' },
    { name: 'barbell lying extension', target: 'triceps' }
  ]
}

然后我使用map()和flatMap()为每一天创建一个训练计划，其中包含当天所有指定肌肉的所有练习。 要为肌肉群创建字符串，我们只需join()肌肉数组。