How to display “%” sign on mouse hover in Pie-Chart

Question

I am drawing graph on UI using ChartJS 2.0. And I am able to render a Pie Chart. But I want the mouse-hover to show the data along with a \"%

Answer 1

You can edit what is displayed in your tooltip with the callbacks.label method in your chart options, and then simply add a "%" to the default string using :

• tooltipItems -- See documentation for more information (scroll up a bit to "Tooltip Item Interface")
• data -- Where the datasets and labels are stored.

var ctx = document.getElementById("canvas");
var data = {
    datasets: [{
        data: [93, 4, 3],
        backgroundColor: [
            "#455C73",
            "#BDC3C7",
            "#26B99A",
        ],
        label: 'My dataset' // for legend
    }],
    labels: [
        "Rented",
        "Vacant",
        "Unavailable",
    ]
};
var pieChart = new Chart(ctx, {
    type: 'pie',
    data: data,
    options: {
        tooltips: {
            callbacks: {
                label: function(tooltipItems, data) {
                    return data.labels[tooltipItems.index] + 
                    " : " + 
                    data.datasets[tooltipItems.datasetIndex].data[tooltipItems.index] +
                    ' %';
                }
            }
        }
    }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.2.1/Chart.min.js"></script>
<canvas id="canvas" height="150"></canvas>