javascript d3 从多重嵌套数组/对象数据集中获取最大值

Question

如何减少一堆深度嵌套的数组并获得某些键的最大值？这是我的数据格式:

var data = [
{
"category": "Cat 1",
"subcategories": [
  {
    "subcategory": "Subcate 1 a",
    "problems": [
      {
        "problem": "Problem 1 a 1",
        "total": 3,
        "breakdown": {
          "moderate": 1,
          "severe": 2
        }
      },
      {
        "problem": "Problem 1 a 2",
        "total": 6,
        "breakdown": {
          "moderate": 5,
          "severe": 1
        }
      }
    ]
  }
]
},
{
"category": "Cat 2",
"subcategories": [
  {
    "subcategory": "Subcate 2 a",
    "problems": [
      {
        "problem": "Problem 2 a 1",
        "total": 8,
        "breakdown": {
          "moderate": 5,
          "severe": 3
        }
      }
    ]
  },
  {
    "subcategory": "Subcat 2 b",
    "problems": [
      {
        "problem": "Problem 2 b 1",
        "total": 4,
        "breakdown": {
          "moderate": 1,
          "severe": 3
        }
      },
      {
        "problem": "Problem 2 b 2",
        "total": 2,
        "breakdown": {
          "moderate": 2,
          "severe": 0
        }
      }
    ]
  }
]
}
]

如何获得“中度”和“严重”每个值的数组？所以在这个例子中我需要

[1,2,5,1,5,3,1,3,2,0]

然后我想做 d3.max(array) 来从中获取最大值。

Answer 1

这是工作fiddle .只需将对象转换为数组，如下所示:

 var array = $.map(data, function(value, index) {
            return [value];
    });

var arr =[];

for(var key in array)
{
    var subcategories = array[key]['subcategories'];
  for(var j in subcategories)
  {    
      var prob = subcategories[j]['problems'];
      for(var i in prob)
      {
           var moderate = prob[i]['breakdown']['moderate'];
           var severe = prob[i]['breakdown']['severe'];
           arr.push(moderate);
           arr.push(severe);
       }
   }
}
alert(arr); //required array
var max = d3.max(arr) //required max value

并循环遍历它并将值保存到最终数组中!