JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://jp.igniteui.com/js/modernizr.min.js"></script>
<script src="https://code.jquery.com/jquery-1.9.1.min.js"></script>
<script src="https://code.jquery.com/ui/1.10.3/jquery-ui.min.js"></script>
<script src="https://cdn-na.infragistics.com/igniteui/latest/js/infragistics.core.js"></script>
<script src="https://cdn-na.infragistics.com/igniteui/latest/js/infragistics.lob.js"></script>
<script src="https://jp.igniteui.com/data-files/adventureworks.min.js"></script>
<link href="https://cdn-na.infragistics.com/igniteui/latest/css/themes/infragistics/infragistics.theme.css" rel="stylesheet"></link>
<link href="https://cdn-na.infragistics.com/igniteui/latest/css/structure/infragistics.css" rel="stylesheet"></link>
<script src="https://cdn-na.infragistics.com/igniteui/latest/js/i18n/infragistics-ja.js"></script>

<table id="grid"></table>

JavaScript

$(function () {
            $("#grid").igGrid({
                autoGenerateColumns: false,
                width: "100%",
                height: "400px",
                columns: [
                    { headerText: "製品 ID", key: "ProductID", dataType: "number", width: "20%" },
                    { headerText: "製品名", key: "Name", dataType: "string", width: "30%" },
                    { headerText: "製品番号", key: "ProductNumber", dataType: "string", width: "20%" },
                    { headerText: "メーカー フラグ", key: "MakeFlag", dataType: "bool", width: "25%" }
                ],
                dataSource: adventureWorks,
                features: [
                    {
                        name: 'GroupBy',
                        columnSettings: [
                            {
                                columnKey: "Name",
                                isGroupBy: true,
                                compareFunc: groupByFirstLetter,
								groupLabelFormatter: function (val) {
									val = val || "";
									return val.substring(0, 1);
								}
                            }
                        ]
                    }
                ]
            });
        });
        function groupByFirstLetter(val1, val2) {
        	val1 = val1 || "";
        	val2 = val2 || "";
        	val1 = val1.substring(0, 1);
        	val2 = val2.substring(0, 1);
        	return val1 > val2 ? 1 : val1 < val2 ? -1 : 0;
        }