javascript - 将变量传递给canvas.js中的数据点

我正在尝试使用数据库数据从canvas.js绘制行线。但是我在将数据传递到数据点时遇到问题。

 $.ajax({
    dataType : "json",
    type: "POST",
    url: base_url + 'index.php/dashboard/line_graph',
    data: {},
    success: function(data)
    {
        for(var i = 0; i < data.length; i++)
        {
            var firstdate = data[i].nextdate;
            var res = firstdate.replace(/[-]/g,',');
            fd += '{ x: new Date(' + res + '), y:' + data[i].count +'},';
        }
        var fin = fd.slice(0,-1);
         finals = "[" + fin + "]";
                var chart = new CanvasJS.Chart("chartContainer",
                  {

                    title:{
                    text: "Booking - per month (DEMO)"
                    },
                     data: [
                    {
                      type: "line",

                      dataPoints: finals

                    }
                    ]
                  });

                  chart.render();

    }
});

当我警报finals并复制时，将警报的数据粘贴到数据点并运行。但是，当将包含相同数据的变量传递到数据点时，它将无法正常工作。

在控制台日志中，出现此错误。

 TypeError: l.dataPoints[q].x is undefined

数据点的格式是这样。当我发出警报时，变量finals也包含相同的数据。

 [
 { x: new Date(2015,03,6), y:4},
 { x: new Date(2015,03,11), y:0},
 { x: new Date(2015,03,16), y:0},
 { x: new Date(2015,03,21), y:0},
 { x: new Date(2015,03,26), y:0},
 { x: new Date(2015,03,31), y:14}
 ]

我的页面返回此json_encode格式。

 [
 {"firstdate":"2015-03-01","nextdate":"2015-03-6","count":"4"},
 {"firstdate":"2015-03-6","nextdate":"2015-03-11","count":"0"},
 {"firstdate":"2015-03-11","nextdate":"2015-03-16","count":"0"},
 {"firstdate":"2015-03-16","nextdate":"2015-03-21","count":"0"},
 {"firstdate":"2015-03-21","nextdate":"2015-03-26","count":"0"},
 {"firstdate":"2015-03-26","nextdate":"2015-03-31","count":"14"}
 ]

我没有问题。请帮忙。

最佳答案

您不必像字符串一样创建finals变量，可以直接使用Javascript的对象格式:

$.ajax({
    type: "POST",
    url: base_url + 'index.php/dashboard/line_graph',
    data: {},
    success: function(data)
    {
        var tabData = JSON.parse(data);
        var finals = [];
        for(var i = 0; i < tabData.length; i++)
        {
            var firstdate = tabData[i].nextdate;
            var res = firstdate.split('-');
            finals.push({ 'x': new Date(res[2],res[1],res[0]), 'y': tabData[i].count });
        }
        var chart = new CanvasJS.Chart("chartContainer",{
            title:{
                text: "Booking - per month (DEMO)"
            },
            data: [
                {
                    type: "line",
                    dataPoints: finals
                }
            ]
        });

        chart.render();
    }
});