Implementing a console.table() like feature to help with debugging

console.table.js

function console_table(xs) {

    function pad(n, s) {
        var res = s;
        for (var i = s.length; i < n; i++)
            res += " ";
        return res;
    }

    if (xs.length === 0)
        console.log("No data");
    else {
        var widths = [];
        var cells = [];
        for (var i = 0; i <= xs.length; i++)
            cells.push([]);
        for (var s in xs[0]) {
            var len = s.length;
            cells[0].push(s);
            for (var i = 0; i < xs.length; i++) {
                var ss = "" + xs[i][s];
                len = Math.max(len, ss.length);
                cells[i + 1].push(ss);
            }
            widths.push(len);
        }
        var s = "";
        for (var x = 0; x < cells.length; x++) {
            for (var y = 0; y < widths.length; y++)
                s += "|" + pad(widths[y], cells[x][y]);
            s += "|\n";
        }
        console.log(s);
    }
}