Chart.js Pie Tooltips

chart-pie-tooltip-part-code.js

            // 關於滑過後的 顯示
            tooltips: {
                callbacks: {
                    label: function (tooltipItem, data) {
                        var dataset = data.datasets[tooltipItem.datasetIndex];
                        //計算總和
                        var sum = dataset.data.reduce(function (previousValue, currentValue, currentIndex, array) {
                            return previousValue + currentValue;
                        });
                        var currentValue = dataset.data[tooltipItem.index];
                        var percent = Math.round(((currentValue / sum) * 100));
                        return " " + data.labels[tooltipItem.index] + ":" + currentValue + " (" + percent + " %)";
                    }
                }
            },