Question

在D3.JS或javascript / jquery中有没有办法做到这一点：

我有一个数组数组..

[
 [{date:x,data:1},{date:x,data:9}],
 [{date:y,data:5},{date:y,data:10},{date:y,data:8}],
 [{date:z,data:2},{date:z,data:5}]
]

我想重新排列它们，以便这个顶级数组中的数组都具有相同的日期：

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  $("#myform").on("change", "input", function(){
    status=($("#myform").find("input:checked").length==0)?"disabled":"";
    $("button").prop("disabled", status);
  })
})

Answer 1

d3非常简单：

xs = [
    [{date: 'x', data: 1}, {date: 'y', data: 5}, {date: 'z', data: 2}],
    [{date: 'x', data: 9}, {date: 'y', data: 10}],
    [{date: 'y', data: 8}, {date: 'z', data: 5}]
]

z = d3.nest()
    .key(x => x.date)
    .sortKeys(d3.ascending)
    .entries(d3.merge(xs))
    .map(x => x.values)


z.map(e => document.write('<pre>'+JSON.stringify(e)+'</pre>'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

Answer 2

使用纯javascript

var x = 'x', y = 'y', z = 'z';
var arr = [
  [{ date: x, data: 1 }, { date: y, data: 5 }, { date: z, data: 2 }],
  [{ date: x, data: 9 }, { date: y, data: 10 }],
  [{ date: y, data: 8 }, { date: z, data: 5 }]
];
var res = arr.reduce(function (result, inArr, index) {
  inArr.forEach(function (obj) {
    result[obj.date] = result[obj.date] || [];
    result[obj.date].push(obj);
  });
  return result;
}, {});

var output = [];
for (var key in res) {
  output.push(res[key]);
}
console.log(output);

将输出

[
 [
  {
   "date": "x",
   "data": 1
  },
  {
   "date": "x",
   "data": 9
  }
 ],
 [
  {
   "date": "y",
   "data": 5
  },
  {
   "date": "y",
   "data": 10
  },
  {
   "date": "y",
   "data": 8
  }
 ],
 [
  {
   "date": "z",
   "data": 2
  },
  {
   "date": "z",
   "data": 5
  }
 ]
]

Answer 3

你可以在没有任何lib的情况下做到这一点：

1）使用键date

创建地图

2）按键分组

3）创建结果集

4）完成

arr=[
 [{date:'x',data:1},{date:'y',data:5},{date:'z',data:2}],
 [{date:'x',data:9},{date:'y',data:10}],
 [{date:'y',data:8},{date:'z',data:5}]
]

function group(a){
    return arr.reduce(function(o,n){
    n.forEach(function(a){
        var key=a.date;
      if(!o[key]) o[key]=[];
      var tmp=o[key];
      tmp.push(a);
      o[key]=tmp;
    });
    return o;
  },{});
}

var resultMap = group(arr);
var result = Object.keys(resultMap).map(
    function(x){
    return resultMap[x];
  }
);
console.log(result)

这里是Fiddle。

Array.prototype.reduce()解释为here

Array.prototype.map()解释为here

如何使用相同的键属性重新排列嵌套数组

3 个答案: