Intermittent JavaScript Issue

Question

I'm running some JavaScript via eval (I know, shoot me), that basically enumerates all of the properties on the document object. My issue is that while it works in firebug, it throws a not implemented exception in Firefox, when run from a script.

Link to JavaScript script, the exception thrown, and the firebug command working.

Any suggestions as to what's going on here?

For the record, this is done on Firefox 3.6.10 on Ubuntu 10.04 64-bit, and chrome does not have this issue.

Answer 1

The error is here:

console.log(result);

remove that line and all should be fine.

The console object is a Firebug thing (refers to the Firebug console). Safari/Chrome just happen to also implement a console object (refers to Webkit js console). Firefox, indeed other browsers don't have a console object. So it throws an error.

BTW: As usual, the evals are completely unnecessary. This is exactly equivalent code:

for (key in document) {
    result[i] = typeof document[key];
    result[i+1]="document."+key;
    i+=2;
}

If you insist on calling it request then use it as a reference:

var request = window.document;
for (key in request) {
    result[i] = typeof request[key];
    result[i+1]=request+"."+key;
    i+=2;
}

If you insist on passing object names by string, then for sanity's sake use eval in a less confusing way:

var string = "window.document";
eval("var request ="+string);
for (key in request) {
    result[i] = typeof request[key];
    result[i+1]=request+"."+key;
    i+=2;
}

Though I wouldn't do even that (sometimes it is necessary, but only very rarely).