javascript - 组合位置并从 JSON 输出组合数据

Question

这个想法是获取所有“位置”并将它们合并在一起以给出一个数字供我的图表读取。假设您有 5 个“地点”，均为纽约，且“日期”各不相同。我想将所有 5 个合并在一起并输出 5 个数字，以及 .json 中合并的“Punches”。现在我让它抓取位置，并合并类似的拳击。但我想获取例如纽约实例的总数并输出该数字。

chart.json

    [  
   {  
      "Date":"2003",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2003",
      "Punches":"1",
      "Locations":"New York"
   },
   {  
      "Date":"2004",
      "Punches":"0",
      "Locations":"Chicago"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Chicago"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Ohio"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Ohio"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"Ohio"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"Florida"
   },
   {  
      "Date":"2009",
      "Punches":"1",
      "Locations":"Florida"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2009",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2009",
      "Punches":"0",
      "Locations":"Chicago"
   },
   {  
      "Date":"2010",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2010",
      "Punches":"0",
      "Locations":"Florida"
   }
]

JS

function LocationMerge()
        {
            $.ajax(
            {
                url: 'data.json',
                data:{},
                dataType: 'json',
                success: function(data)
                {
                    var string = JSON.stringify(data);
                    var objects = $.parseJSON(string);
                    var categories = new Array();
                    var mergedPieces = new Array();
                    var i = 0;
                    _.each(objects, function(obj)
                    {
                        var existingObj;
                        if ($.inArray(obj.Locations, categories) >= 0)
                        {
                            existingObj = _.find(objects, function(o)
                            {
                                return o.Locations=== obj.Locations;
                            });
                            existingObj["Punches"] += obj["Punches"];
                        }
                        else
                        {
                            mergedPieces[i] = obj;
                            categories[i] = obj.Locations;
                            i++;
                        }
                    });
                    mergedPieces = _.sortBy(mergedPieces, function(obj)
                    {
                        return obj["Punches"];
                    }).reverse();
                    _.each(mergedPieces, function(obj)
                    {
                        var output = '';
                        _.each(obj, function(val, key)
                        {
                            output += key + ': ' + val + '<br>';
                        });
                        output += '<br>';
                        console.log(output);
                    });
                }
            });
        }

Answer 1

Code below

var dataset = [  
   {  
      "Date":"2003",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2003",
      "Punches":"1",
      "Locations":"New York"
   },
   {  
      "Date":"2004",
      "Punches":"0",
      "Locations":"Chicago"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Chicago"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Ohio"
   },
   {  
      "Date":"2004",
      "Punches":"1",
      "Locations":"Ohio"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"Ohio"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"Florida"
   },
   {  
      "Date":"2009",
      "Punches":"1",
      "Locations":"Florida"
   },
   {  
      "Date":"2007",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2009",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2009",
      "Punches":"0",
      "Locations":"Chicago"
   },
   {  
      "Date":"2010",
      "Punches":"0",
      "Locations":"New York"
   },
   {  
      "Date":"2010",
      "Punches":"0",
      "Locations":"Florida"
   }
];

map = {};
dataset.forEach(function(data){ if(map[data.Locations]){map[data.Locations]=map[data.Locations]+1}else{map[data.Locations]=1}});

snippet.log(map)

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