bored extend... for kicks

extend.js

var extend = function (dest) {
  var args = Array.prototype.slice.call(arguments, 1),
      ln = args.length;
  for (var i=0;i<ln;++i) {
    for (var o in args[i]) {
      dest[o] = args[i][o];
    }
  };
  return dest;
};

test.js

var dest = {
  key: 'val2',
  priv: 'val4'
};

var opts = {
  key: 'val1',
  priv: 'val3',
  meow: 'cat'
};

var opts2 = {
  key: 'val5',
  meow: 'kitten'
};

console.log(extend(dest, opts, opts2));