Question

I have an app using requirejs in a pretty simple method:

define([
    'jquery',
    'scriptone',
    'scripttwo'
], function ($,scriptone,scripttwo) {

for(var i=0, max=arguments.length; i<max; i++){

    // What is the name of the argument ????

}

});

In the for loop I would like to be able to retrieve the name of the argument so as this loops through it would return ‘$’, ‘scriptone’, ‘scripttwo’ …

I know this is ultimately a question about functions and arguments, just wondering if in the context of RequireJS there is a simple/good method to achieve this?

Answer 1

You should never ever need to know variable names at runtime. There’s something wrong with your application.

However, you can do it. Get a serialisation of the function, remove comments etc, and parse the arguments list. To get the function itself, you might use deprecated arguments.callee but better get a named reference to it. So you might end up with

var fn = arguments.callee.toString();
var args = fn
  .replace(/\/\/.*?\n|\/\*.*?\*\//g, "") // remove comments
  .match(/^function\s*\S*\s*\(\s*(.+?)\s*\)/)[1] // match arguments list
  .split(/\s*,\s*/) // get argument names
for (var i=0; i<arguments.length; i++)
  console.log((args[i] || "unnamed argument")+":", arguments[i]);