将新列表添加到现有 java 脚本对象

Question

我正在尝试填充条形图的数据集。我想将 'dataset' 添加到现有的 barData1 对象。

但是我遇到了以下错误。我在这里做错了什么？

error: jquery-3.1.1.min.js:2 Uncaught TypeError: Cannot read property 'splice' of undefined

<script type="text/javascript">
var jsprojStatList = @Html.Raw(ViewBag.projStatList);

    $(document).ready(function () {
        var barData1 = {
            labels: ["No. Of Line Items", "Line Items Ordered", "( % )", "Line Items to be Ordered", "( % )", "PO Generated", "PO Approved", "PO Waiting for Approval"]
        };
        //var obj = JSON.parse(barData1);
        //var parse_obj = JSON.parse(barData1);
        var i = 0;
        for (var key in jsprojStatList) {
            if (jsprojStatList.hasOwnProperty(key)) {
                var val = jsprojStatList[key];
                barData1['datasets'].splice(i, 0, {
                    "label": val.BudgetTypeTitle, "backgroundColor": "rgba(220, 220, 220, 0.5)", "rgba(220, 220, 220, 0.5)": "#fff"
                    , "data": [val.NoOfBudgetItems, val.NoOfBudgetItemsOrdered, val.NoOfBudgetItemsOrderedPercentage, val.NoOfBudgetItemsToBeOrdered
                        , val.NoOfBudgetItemsToBeOrderedPercentage, val.POGenerated, val.POApproved, (val.POGenerated - val.POApproved)]
                });
                i++;
                };
        };
        //}

        var barOptions1 = {
            responsive: true
        };

        var ctx21 = document.getElementById("barChart1").getContext("2d");
        new Chart(ctx21, { type: 'bar', data: barData1, options: barOptions1 
    });
</script>

Answer 1

您必须先将 barData1['datasets'] 本身定义为数组，然后才能向其添加值：

var barData1 = {
    datasets: [], // populated below
    labels: ["No. Of Line Items", "Line Items Ordered", "( % )", "Line Items to be Ordered", "( % )", "PO Generated", "PO Approved", "PO Waiting for Approval"]
};

.splice() 不会在第一次使用时t/can 自动为您创建数组。

旁注：

由于您似乎没有将 i 用于其他用途，因此可以使用 .push(value) 代替 .splice(i, 0, value)。那会让你丢弃 var i = 0 和 i++.
如果jsprojStatList是一个Array（根据名字中的List猜测），a for..in loop isn't usually appropriate with them.

将新列表添加到现有 java 脚本对象

Adding new list to existing java script object

javascript

arrays

dataset

splice