README.md

What is the best way to inject a value into the middle of arguments?

1. Would prefer it to be a one liner
2. Need it to be really fast!

JSPerf here: http://jsperf.com/inject-into-arguments

Of the two below "slice-and-concat.js" is 12% faster in Chrome.

slice-and-concat.js

function fn() {
  return [arguments[0],'INJECTED VALUE'].concat(Array.prototype.slice.call(arguments, 1));
}
fn(1, 2, 3, 4);

slice-and-splice.js

function fn() {
  var args = Array.prototype.slice.call(arguments);
  args.splice(1,0,'INJECTED VALUE');
  return args;
}
fn(1, 2, 3, 4);