P33

// In Firefox, press Ctrl+Shift+K then copy and paste.

function printStar(n)
{
    var output = "";
    var level = n*2+1;

    for(var i = 1; i <= level; i++)
    {
        var isOddRow = i%2 == 1;
        var row = Math.floor((i+1)/2);
        var star = i < level ? row*2+1 : (row-1)*2+1;
        for(var j = 1; j <= star; j++)
        {
            var isOddCol = j%2 == 1;
            output += isOddRow || (!isOddRow && isOddCol) ? "*" : "-";
        }
        output += "\r\n";
    }
    return output;
}
print(printStar(3));