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Re: Get value of named object

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

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Get value of named object Swifty <steve.j.swift@gmail.com> - 2011-10-22 11:56 +0100
  Re: Get value of named object "Evertjan." <exjxw.hannivoort@interxnl.net> - 2011-10-22 11:20 +0000
    Re: Get value of named object Swifty <steve.j.swift@gmail.com> - 2011-10-22 18:57 +0100
      Re: Get value of named object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-22 21:20 +0200
  Re: Get value of named object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-22 14:35 +0200
    Re: Get value of named object Swifty <steve.j.swift@gmail.com> - 2011-10-22 18:59 +0100
      Re: Get value of named object Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-22 21:22 +0200
  Re: Get value of named object Scott Sauyet <scott.sauyet@gmail.com> - 2011-10-22 12:53 -0700
  Re: Get value of named object Lasse Reichstein Nielsen <lrn.unread@gmail.com> - 2011-10-23 02:10 +0200
    Re: Get value of named object Swifty <steve.j.swift@gmail.com> - 2011-10-23 09:01 +0100
      Re: Get value of named object Lasse Reichstein Nielsen <lrn.unread@gmail.com> - 2011-10-23 11:57 +0200
        Re: Get value of named object Swifty <steve.j.swift@gmail.com> - 2011-10-24 14:11 +0100
  Re: Get value of named object Dr J R Stockton <reply1142@merlyn.demon.co.uk> - 2011-10-23 21:16 +0100

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