如何对数组内的对象进行分组

Question

这就是我所拥有的

 [
   {
     typeProgramId: {
       name: 'type1',
     },
     title: 'test1',
   },
   {
     typeProgramId: {
       name: 'type1',
     },
     subTypeProgramId: [{
       name: 'sub1',
     }],
     title: 'test2',
   },
  {
     typeProgramId: {
       name: 'type2',
     },
     title: 'test3',
   },
   {
     typeProgramId: {
       name: 'type2',
     },
     subTypeProgramId: {
       name: 'sub2',
     },
     title: 'test4',
   }
 ]

首先，如果标题具有相同的 typeProgramId，我想对 typeProgramId 进行分组，我想按每个 typeProgramId 将标题推送到数组中，但是如果数据具有 typeProgramId 和 subTypeProgram Id，我也想在 typeProgramId 中对 subtypeProgramId 进行分组。如果不为空 subtypeProgramId 我想将它推送到 subtypeProgram Id 内的数组标题中。我尝试使用 lodash groupBy 和多种方式，但仍然无法正常工作。

这就是我想要的

{
    typeProgramId: [{
        name: 'type1',
        title: [
            'test1',
        ],
        subTypeProgramId: {
            name: sub1,
            title: [
                'test2'
            ]
        }
    }, {
        name: 'type2',
        title: [
            'test3',
        ],
        subTypeProgramId: [{
            name: sub1,
            title: [
                'test4'
            ]
        }
    }]
}

我现在在做什么

  let result = _.groupBy(getProgram, function(data) {
    return data.typeProgramId
  })
  result = _.map(result, function(group, data) { 
    // I think in here I must groupBy subTypeProgramId again 
    // the data return all string not object after group 
    return {
      typeProgramId: data,
      titile: group,
    }
  })

Answer 1

请检查以下代码。我使用了数组的reduce 函数。它产生了预期的结果。

function updateMem(mem, prgIndex, val){
    if(prgIndex < 0) {
      mem.typeProgramId.push({});
      prgIndex = mem.typeProgramId.length - 1;
    }

    mem.typeProgramId[prgIndex].name = val.typeProgramId.name;

    if(val.subTypeProgramId){
      mem.typeProgramId[prgIndex].subTypeProgramId = Object.assign({}, mem.typeProgramId[prgIndex].subTypeProgramId || {}, {"name" : val.subTypeProgramId.name, "title": []});
      mem.typeProgramId[prgIndex].subTypeProgramId.title.push(val.title);
      
    } else {
      mem.typeProgramId[prgIndex].title = (mem.typeProgramId[prgIndex].title ? mem.typeProgramId[prgIndex].title : []);
      mem.typeProgramId[prgIndex].title.push(val.title);
    }
};

arr.reduce((mem, val) => {
  var prgIndex = mem.typeProgramId.findIndex((p) => p.name === val.typeProgramId.name);
  updateMem(mem, prgIndex, val);
  return mem;
}, {typeProgramId: []});