Hidden javascript properties

Javascript contains hidden properties in many objects, I first discovered this when DoctorDan from the slackers forum demonstrated a technique to get the text from a regular expression object without specifying the source property. Later I found a post by John Resig about weird IE behavior again with -1 properties.

So I decided to experiment and write a little script to investigate further. I discovered that it's possible to access strings of global object names. For example:-

<pre lang="javascript"> alert(Boolean[-6]); alert(typeof Boolean[-6]); </pre>

It seems that Firefox at least stores names of objects in "-6", the example above returns the value "Boolean" as a string. Here's a few examples I posted slackers which use Objects to create strings.

This is the simple script I wrote to find the properties, feel free to experiment and find any other "hidden" gems.

<pre lang="javascript"> function inspectObject(obj) { var prop; var props = []; for(var i=-1000;i<1000;i++) { if(i > 0) { prop = obj[String.fromCharCode(i)]; if(prop != null) { props.push(String.fromCharCode(i) + '=' + prop); } } else { prop = obj[i]; if(prop != null) { props.push(i + '=' + prop); } } } return props; } x=function x(){}; inspectObject(x) </pre>