Latest Keydown Time

var t = 0;
var h = [];
var long = 0;
var short = Infinity;
var avg = 0;

document.body.style.textAlign = 'right';

document.addEventListener('keydown', function(e) {

    c = ~~(e.timeStamp - t);
    h.push(c);
    long = long<c?c:long;
    short = short>c?c:short;

    var sum = 0;
    for( var i = 0; i < h.length; i++ ) {
        sum += h[i];
    }
    avg = ~~(sum/h.length);

    document.body.innerHTML = '<center><h1>Latest Keydown Time</h1></center>Current ' + c + 'ms</br>Longest ' + long + 'ms</br>Shortest ' + short + 'ms</br>Average ' + avg + 'ms</br>';

    t = e.timeStamp;
})