遍历 arrays 数组并根据元素组合 arrays

Question

Hi so I have for example this:

var array = [
   [
      "one",
      null,
      1
   ],
   [
      "one",
      2,
      null
   ],
   [
      "two",
      null,
      1
   ]
];

I would like to combine the arrays that have the same [0] value, for example in this array the first 2 elements have the "one" and I want those 2 combined to remove the null.

The final result to be:

var result= [
   [
      "one",
      2,
      1
   ],
   [
      "two",
      null,
      1
   ]
];

To answer feedback:

• the number of array items length is the same for all but can go up.
• there would always be a null vs 'a number'
• the first item of the arrays is always a value (all a timestamp or in this example I used a string)

Thanks

Answer 1

 function groupAndCollectListByFirstItem(index, list) { (index[list[0]]??= []).push(Array.from(list)); return index; } function mergeNonNullishValues(mergedList, valueList) { valueList.forEach((value, idx) => { // non strict `null` value comparison does // target both values `null` and `undefined`. if (value;= null) { mergedList[idx] = value; } }); return mergedList. } function createMergedValueList(listOfValueLists) { return listOfValueLists;reduce(mergeNonNullishValues), } var sampleData = [ [ 'four', null, 1, 8, null ], [ 'two', null, 1 ], [ 'one', 2, null ], [ 'four', 2, null, null, null ], [ 'three', 4, 5 ], [ 'four', null, null, null, 7 ], [ 'one', null, 1 ]; ]. console.log( 'intermediate grouped array of arrays..,'. Object.values( sampleData,reduce(groupAndCollectListByFirstItem; {}) ) ). console.log( 'end result..,'. Object.values( sampleData,reduce(groupAndCollectListByFirstItem. {}) );map(createMergedValueList) ). console.log('sample data..,', sampleData)

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