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Re: Adding extra element "to option list" using next loop?

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Den måndag 26 november 2018 kl. 13:05:57 UTC+1 skrev Evertjan.:
> =?UTF-8?Q?Jonas_Th=C3=B6rnvall?= <jonas.thornvall@gmail.com> wrote on 26
> Nov 2018 in comp.lang.javascript: 
> 
> > Den lördag 24 november 2018 kl. 09:40:40 UTC+1 skrev Jonas Thörnvall:
> >> I have a hard time understand the intrisic works of next loops, i use
> >> exa 
> > mples i found on net onto create an optionlist of "devices".
> >> 
> >> But i want to add an extra "option to the list of my own", but since i
> >> do 
> >  not understand the inner works of next loop, i am a bit stumped howto
> >  add my extra alternative to the option list. Here i try to add it
> >  before, and i also tried after. But i do not know howto position myself
> >  relative the next loop? 
> >> 
> >> Could someone please show me?
> >> 
> >>   var optout = document.createElement("option");
> >>   optout.text = "WEB SF2 SYNTH MY ADDED ADDED ALTERNATIVE";
> >>   document.getElementById("out_portsel").add(optout);
> >>   for (listoutput = Lportout.next(); listoutput && !listoutput.done; li
> > stoutput = Lportout.next()) {
> >>     var deviceOut = listoutput.value.name;
> >>     optout.text = deviceOut;
> >>     document.getElementById("out_portsel").add(optout);
> >>   }
> > 
> > What is the reason for this code not showing any element within loop
> > just the extra added option? It seem to me it should add to the elements
> > created in loop? 
> > 
> >  var optout = document.createElement("option");
> >   for (listoutput = Lportout.next(); listoutput && !listoutput.done;
> >   listoutput = Lportout.next()) { 
> >     var deviceOut = listoutput.value.name;
> >     optout.text = deviceOut;
> >     document.getElementById("out_portsel").add(optout);
> >   }
> >   test= document.getElementById("out_portsel");
> >   optout.text = "SF2 SYNTH WEB";
> >   test.add(optout);
> 
> You will need a NEW optout each time, meThinks():
> 
> [ES2015]
> for (...) {
>     const optout = document.createElement("OPTION");
>     ...
>     document.getElementById("out_portsel").appendChild(optout);
> };
> 
> 
> 
> -- 
> Evertjan.
> The Netherlands.
> (Please change the x'es to dots in my emailaddress)

Maybe i missunderstand you, but the loop reading ports/devices into the option list work just fine no matter how many ports devices i have. 

The problem arise when i want to add a pseudo port of my own to the list before, after or at index an index.

Before it will be overwritten in loop, after it will be the only option element.
JT

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Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-24 00:40 -0800
  Re: Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-24 05:35 -0800
  Re: Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-25 19:57 -0800
    Re: Adding extra element "to option list" using next loop? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2018-11-26 13:05 +0100
      Re: Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-26 22:45 -0800
        Re: Adding extra element "to option list" using next loop? Jake Jarvis <pig_in_shoes@yahoo.com> - 2018-11-27 10:30 +0100
          Re: Adding extra element "to option list" using next loop? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2018-11-27 12:08 +0100
            Re: Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-27 12:43 -0800
              Re: Adding extra element "to option list" using next loop? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2018-11-27 23:39 +0100
                Re: Adding extra element "to option list" using next loop? Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-11-28 20:25 -0800

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