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Swifty <> writes:

> If I have the name of an object in a variable, how would I go about
> getting the value of that object?
>
> Example:
> varname = 'navigator.appName';
>

So this is the reference:
globalObject["navigator"]["appName"]

So:
<script>
var global = this;
function EvalReference(name) {
var parts = name.split(/\./g);
var current = global;
for (var i = 0; i < parts.length; i++) {
current = current[parts[i]];
}
return current;
}
</script>

Then you can do:
EvalReference("navigator.appName"]
and get the expected result.

Yes, you can use eval instead. You must be certain to use global eval,
by calling it as an indirect call (not called "eval"). E.g.,
var indirectEval = eval;
var value = indirectEval("navigator.appName");
I still think it's a bad idea.

/L
--
Lasse Reichstein Holst Nielsen
'Javascript frameworks is a disruptive technology'

In comp.lang.javascript message <a185a7pdddj3ui58j7a8rrtuivpe4gu92l@4ax.
com>, Sat, 22 Oct 2011 11:56:39, Swifty <>
posted:

>If I have the name of an object in a variable, how would I go about
>getting the value of that object?
>
>Example:
>varname = 'navigator.appName';
>
>How would I get the value of navigator.appName ?


var Arr = varname.split(".") // gives ["navigator","appName"]

IIRC, there are only a few possibilities for Arr[0], so
var Obj = {"navigator": navigator; "document": document /*, ,,, */}
is feasible.

var Obj = {"navigator": navigator, "document": document,
"Math": Math /*, ,,, */}

var varname = 'navigator.appName';
var Arr = varname.split(".")
Result = Obj[Arr[0]][Arr[1]]

gives "Netscape", and for "Math.PI" gives about 22/7, and for
"document.writeln" gives "function writeln() { [native code]}".
Now make that a function.

To allow for inputs with other than one dot, start with Result=Obj, then
iterate through Arr (in the right direction) doing each index in turn.
Untested, therefore code not written here.

You might like <http://www.merlyn.demon.co.uk/js-props.htm>.

>The idea is to replace the multiple "document.write" lines with the
>simpler "show()" calls.

Consider
var Arr = []
Arr.push("6")
Arr.push(" fred")
document.write(A,join(""))
which is less typing per line of code.

--
(c) John Stockton, nr London, UK. ?@merlyn.demon.co.uk Turnpike v6.05.
Website <http://www.merlyn.demon.co.uk/> - w. FAQish topics, links, acronyms
PAS EXE etc. : <http://www.merlyn.demon.co.uk/programs/> - see in 00index.htm
Dates - miscdate.htm estrdate.htm js-dates.htm pas-time.htm critdate.htm etc.