Chart.js V2: Add prefix or suffix to tooltip label

Question

In Chart.js V1.0, I would add tooltipTemplate: \"<%if (label){%><%=label %>: <%}%><%= \'€\' + value %>\" to add a euro symbol as prefix

Answer 1

This set "label + value + €"

options: {
    legend: {
        display: false
    },
    tooltips: {
        callbacks: {
            label: function(tooltipItem, data) {
                return data.labels[tooltipItem.index] + ': ' + data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index] + '€';
            }
        }
    }
}