slice arguments

slice_args.js

(function() {
var bench = function(func, t) {
  var start = new Date()
    , i = t || 100000;
  while (i--) func(1, 2, 3);
  console.log('%s: %sms', func.name, new Date() - start);
};

var slice = Array.prototype.slice;
bench(function _slice() {
  var args = slice.call(arguments);
  args.unshift(1);
});

bench(function _for() {
  var l = arguments.length;
  var args = new Array(l + 1);
  args[0] = 1;
  for (var i = 0; i < l; i++) args[i+1] = arguments[i];
});
})();