javascript - 在 jquery 中创建新的垂直 json 到水平

Question

我有一个如下所示的 JSON

 var data = [

        { "year": 2013, "month": 10, "week": 41, "changes": 1590 },
        { "year": 2013, "month": 10, "week": 42, "changes": 0 },
        { "year": 2013, "month": 10, "week": 43, "changes": 2008 },
        { "year": 2013, "month": 10, "week": 44, "changes": 3900 },
        { "year": 2014, "month": 10, "week": 41, "changes": 1052 },
        { "year": 2014, "month": 10, "week": 42, "changes": 0 },
        { "year": 2014, "month": 10, "week": 43, "changes": 10122 },
        { "year": 2014, "month": 10, "week": 44, "changes": 1461 },
        { "year": 2015, "month": 10, "week": 41, "changes": 682 },
        { "year": 2015, "month": 10, "week": 42, "changes": 0 },
        { "year": 2015, "month": 10, "week": 43, "changes": 244 },
        { "year": 2015, "month": 10, "week": 44, "changes": 21 }

    ];

我想生成这个 JSON 之类的东西

var firstYear = "2013";
    var secondYear = "2014";
    var thildYear = "2015";

    var sampleData = [
        { "week": 41, "firstYear": 1590, "secondYear": 1052, "thildYear": 682 },
        { "week": 42, "firstYear": 0, "secondYear": 0, "thildYear": 0 },
        { "week": 43, "firstYear": 2008, "secondYear": 10122, "thildYear": 244 },
        { "week": 44, "firstYear": 858, "secondYear": 1461, "thildYear": 21 }
    ];

我写了一段代码，但它不起作用

  var jsonObjdata = [];
    var yearExist = "";
    var weekExist = "";
    var SampleRequestBody = {};
    $.each(data, function (key, value) {
        if (value.year != yearExist) {
            SampleRequestBody.week = value.week;
            SampleRequestBody.firstYear = value.changes;
            yearExist = value.year;
        }
        else if (value.year == yearExist && value.week == weekExist + 1) {
            SampleRequestBody.secondYear = value.changes;
        }
        else if (value.year == yearExist && value.week == weekExist + 1) {
            SampleRequestBody.thildYear = value.changes;
            jsonObjdata.push(SampleRequestBody);
        } 
    });

你能帮我吗？

Answer 1

这是使用 array.prototype.reduce 的另一种方式。 :

var weeks = [], flatData;
flatData = data.reduce(function(outData, obj) {
    var tmp = {}, prop = 'year' + obj.year;
    if ((idx = weeks.indexOf(obj.week)) >= 0) {
        outData[idx][prop] = obj.changes;
    } else {
        weeks.push(obj.week);
        tmp['week'] = obj.week;
        tmp[prop] = obj.changes;
        outData.push(tmp);
    }
    return outData;
}, []);

它将返回一个像这样的对象数组:

week    year2013    year2014    year2015
----    --------    --------    --------
41      1590        1052        682
42      0           0           0
43      2008        10122       244
44      3900        1461        21

演示 fiddle :http://jsfiddle.net/abhitalks/kLg5f1wk/ (检查控制台)

演示片段: (检查控制台)

var data = [
        { "year": 2013, "month": 10, "week": 41, "changes": 1590 },
        { "year": 2013, "month": 10, "week": 42, "changes": 0 },
        { "year": 2013, "month": 10, "week": 43, "changes": 2008 },
        { "year": 2013, "month": 10, "week": 44, "changes": 3900 },
        { "year": 2014, "month": 10, "week": 41, "changes": 1052 },
        { "year": 2014, "month": 10, "week": 42, "changes": 0 },
        { "year": 2014, "month": 10, "week": 43, "changes": 10122 },
        { "year": 2014, "month": 10, "week": 44, "changes": 1461 },
        { "year": 2015, "month": 10, "week": 41, "changes": 682 },
        { "year": 2015, "month": 10, "week": 42, "changes": 0 },
        { "year": 2015, "month": 10, "week": 43, "changes": 244 },
        { "year": 2015, "month": 10, "week": 44, "changes": 21 }

], weeks = [], flatData;

flatData = data.reduce(function(outData, obj) {
    var tmp = {}, prop = 'year' + obj.year;
    if ((idx = weeks.indexOf(obj.week)) >= 0) {
        outData[idx][prop] = obj.changes;
    } else {
        weeks.push(obj.week);
        tmp['week'] = obj.week;
        tmp[prop] = obj.changes;
        outData.push(tmp);
    }
    return outData;
}, []);

console.table(flatData);