Fetching all (javascript) global variables in a page

Question

Is there a way to retriev the name/value of all global variables on a page?

I would like to write a javascript function to do the following:

1. Find all global variables prefixed with 'xxx_' and stick them in an array (for e.g.)
2. build a query string using the name value pairs as follows: xxx_glob_var1=value1&xxx_glob_var2=value2 etc

Could anyone offer some snippets to show how I may do this?

Answer 1

You could do something like this:

for (var i in window) {
    // i is the variable name
    // window[i] is the value of the variable
}

Though with this, you'll get a bunch of extra DOM properties attached to window.

Answer 2

Something like this:

function getGlobalProperties(prefix) {
  var keyValues = [], global = window; // window for browser environments
  for (var prop in global) {
    if (prop.indexOf(prefix) == 0) // check the prefix
      keyValues.push(prop + "=" + global[prop]);
  }
  return keyValues.join('&'); // build the string
}

A test usage:

var xxx_foo = "foo";
xxx_bar = "bar";
window.xxx_baz = "baz";

var test = getGlobalProperties('xxx_');
// test contains "xxx_baz=baz&xxx_bar=bar&xxx_foo=foo"