javascript - 如何根据重复键合并/组合对象数组？

Question

我正在尝试合并任何重复键上的数据，同时重写数据对象。

我正在尝试根据每个对象是否具有相同的“时间”来合并值数组。之后，我想将项目中的每个值与名称配对。

我觉得最简单的展示方式就是通过我希望转化的原始数据，所以我想转化如下；

var data = [{
  "item": ["1", "2"],
  "time": "12-15",
  "name": "ben"
}, {
  "item": ["3", "4"],
  "time": "12-15",
  "name": "bill"
}, {
  "item": ["1", "2", "3"],
  "time": "15-18",
  "name": "ben"

}, {
  "item": ["4", "5", "6"],
  "time": "15-18",
  "name": "bill"
}];

进入

var result = [{
  "time": "12-15",
  "ben": ["1", "2"],
  "bill": ["3", "4"]
},
{
  "time": "15-18",
  "ben": ["1", "2", "3"],
  "bill": ["4", "5", "6"]
}]

我一直在尝试这个this问题来帮助我做到这一点，但我并没有走得太远。我似乎无法解决第一个选中的项目未作为数组输出的问题。

非常感谢任何帮助!

var data = [{
  "item": ["1", "2"],
  "time": "12-15",
  "name": "ben"
}, {
  "item": ["3", "4"],
  "time": "12-15",
  "name": "bill"
}, {
  "item": ["1", "2", "3"],
  "time": "15-18",
  "name": "ben"

}, {
  "item": ["4", "5", "6"],
  "time": "15-18",
  "name": "bill"

}];



var seen = {};
var result = data.filter(function(entry) {
  var previous;

  // Have we seen this label before?
  if (seen.hasOwnProperty(entry.time)) {

    // Yes, grab it and add this data to it
    previous = seen[entry.time];
    previous.item.push(entry.item);

    // Don't keep this entry, we've merged it into the previous one
    return false;
  }
  //console.log(seen)
  // entry.data probably isn't an array; make it one for consistency
  if (!Array.isArray(entry.item)) {
    entry.item = [entry.item];
  }

  // Remember that we've seen it
  seen[entry.time] = entry;

  // Keep this one, we'll merge any others that match into it
  return true;
});

console.log(result)

Answer 1

您可以使用哈希表进行分组。

var data = [{ "item": ["1", "2"], "time": "12-15", "name": "ben" }, { "item": ["3", "4"], "time": "12-15", "name": "bill" }, { "item": ["1", "2", "3"], "time": "15-18", "name": "ben" }, { "item": ["4", "5", "6"], "time": "15-18", "name": "bill" }],
    result = [];

data.forEach(function (a) {
    if (!this[a.time]) {
        this[a.time] = { time: a.time };
        result.push(this[a.time]);
    }
    this[a.time][a.name] = (this[a.time][a.name] || []).concat(a.item);
}, Object.create(null));

console.log(result);

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

或者对于 ES6，您可以使用 Map .

var data = [{ "item": ["1", "2"], "time": "12-15", "name": "ben" }, { "item": ["3", "4"], "time": "12-15", "name": "bill" }, { "item": ["1", "2", "3"], "time": "15-18", "name": "ben" }, { "item": ["4", "5", "6"], "time": "15-18", "name": "bill" }],
    map = new Map,
    result = [];

data.forEach(a => {
    var o = map.get(a.time);
    if (!o) {
        o = { time: a.time };
        map.set(a.time, o);
        result.push(o);
    }
    o[a.name] = (o[a.name] || []).concat(a.item);
});

console.log(result);

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