Sorting the order history table on david silver spares' website. Custom map/reduce/forEach function because browser natives were overwritten. Just an exercise for fun.

orders-sort.js

function forEach(a, fn) {
    var i;
    for (i in a) {
        if (a.hasOwnProperty(i)) {
            fn.call(null, a[i], i, a);
        }
    }
}

function map(a, fn) {
    var i, r = [];
    for (i in a) {
        if (a.hasOwnProperty(i)) {
            r[r.length] = fn.call(null, a[i], i, a);
        }
    }
    return r;
}

function reduce(a, fn, seed) {
    var i;
    for (i in a) {
        // If seed is omitted, pick the first value of a as the seed
        if (typeof(seed) === "undefined") {
            seed = a[i];
        } else {
            if (a.hasOwnProperty(i)) {
                seed = fn.call(null, seed, a[i], i, a);
            }
        }
    }
    return seed;
}

function sortcmp(a, b) {
    return reduce(
        map([b, a], function (row) {
            return parseInt(row.querySelector("td").innerText, 10);
        }),
        function (s, v) {
            return Math.min(Math.max(-1, s - v), 1);
        }
    );
}

var container = document.querySelector("#cartcontents");
var rows = [].slice.call(container.querySelectorAll("tr"), 1);

forEach(map(
    rows,
    function (tr) {
        return tr.parentNode.removeChild(tr);
    }
).
sort(sortcmp),
function (tr) {
    container.appendChild(tr);
});