Adding a ‘thousands’ separator to ChartJS’s Y axis and tooltips

I learned the toLocaleString() method for adding thousands separators from this Github issue (https://github.com/chartjs/Chart.js/issues/411)

These options in your options config will add a thousands separator to your tooltips and yAxes.

options: {
  tooltips: {
    callbacks: {
      label: function(tooltipItems, data) {
        return data.labels[tooltipItems.index] + ": " + data.datasets[0].data[tooltipItems.index].toLocaleString();
      }
    }
  },
  scales: {
    yAxes: [{
      ticks: {
        beginAtZero: false,
        callback: function(value, index, values) {
          return value.toLocaleString();
        }
      }
    }]
  }
}