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Re: How to manipulate integer that sometimes Nan and sometimes have a value?

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jonas.thornvall@gmail.com wrote on 26 Sep 2015 in comp.lang.javascript:

>> An index of an array CANNOT be empty,
>> because then it would not be an index. 
> 
> Ok ok, Evertjan the element of index is NaN.

Well, I think it pays to be more exact.

"The element OF an array HAVING a certain index."

>> Till you are in a leading position,
>> I would not trust you to do an operation.
> 
> Well that is the problem with doing carry operations using array
> elements as digitplaces, you do not know if the element for the index
> previously occupied by an integer or not.

You should know, otherways your code is not logical.

If a specific array-element is initialized, 
how can it be occupied by something else 
than what you want it to initialize with?

If a specific array-element is not initialized [or deleted],
it is not "empty" but "undefined".

> And if not you have to initialise it to an integer.

Only if that integer is the result of your computation.

Putting 0 into "undefined" array-elements 
expects too much of your specific algorithm,
better make another algorithm for those cases.

> The main case is of course you add one to
> the array element.

Not at all "ofcourse". 
Perhaps you want it that way in this case,
then say so: "I want this and that".

> But if it is a leading carry operation 

What is a  "leading carry operation" 

> the element for the index will hold NaN. 

So it could hold the NaN-value?

I don't think so.

[The NaN-value being a special case of type Number.]

Could it hold a string or an object perhaps?

I don't believe that.
I think it the specific array-element is simply not intitialised, 
so when asked for it 

alert( myArr[i] );

it returns 'undefined'.

So do this:

if (typeof myArr[i] != 'undefined') ...


-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-25 07:31 -0700
  Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-25 17:09 +0200
    Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-25 14:43 -0700
      Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 08:54 +0200
    Re: How to manipulate integer that sometimes Nan and sometimes have a value? Erwin Moller <erwinmollerusenet@xs4all.nl> - 2015-09-30 15:04 +0200
      Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-30 21:13 +0200
        Re: How to manipulate integer that sometimes Nan and sometimes have a value? Erwin Moller <erwinmollerusenet@xs4all.nl> - 2015-10-01 10:44 +0200
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-10-01 13:56 +0200
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? John Harris <niam@jghnorth.org.uk.invalid> - 2015-10-02 11:09 +0100
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-02 13:55 +0100
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-10-02 16:34 +0200
  Re: How to manipulate integer that sometimes Nan and sometimes have a value? Danny <dann90038@gmail.com> - 2015-09-25 15:11 -0700
    Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-25 17:50 -0700
      Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 08:59 +0200
        Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-26 04:25 -0700
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 15:00 +0200
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-26 06:15 -0700
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 15:34 +0200
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-26 08:06 -0700
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? Tim Streater <timstreater@greenbee.net> - 2015-09-26 18:10 +0100
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 22:53 +0200
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? Tim Streater <timstreater@greenbee.net> - 2015-09-26 22:37 +0100
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-27 10:05 +0200
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-27 08:42 -0700
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? Tim Streater <timstreater@greenbee.net> - 2015-09-27 17:18 +0100
      Re: How to manipulate integer that sometimes Nan and sometimes have a value? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-26 10:59 +0100
        Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 13:15 +0200
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-26 14:58 +0100
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 16:57 +0200
        Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-26 04:28 -0700
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 15:11 +0200
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-09-26 17:19 +0200
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-26 22:51 +0200
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-09-27 13:50 +0200
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-26 20:51 +0100
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-28 22:45 -0700
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-09-29 12:36 +0200
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-29 12:48 +0100
        Re: How to manipulate integer that sometimes Nan and sometimes have a value? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-09-26 14:43 +0200
          Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-26 06:06 -0700
            Re: How to manipulate integer that sometimes Nan and sometimes have a value? John Harris <niam@jghnorth.org.uk.invalid> - 2015-09-27 14:06 +0100
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-27 08:50 -0700
              Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-27 08:53 -0700
                Re: How to manipulate integer that sometimes Nan and sometimes have a value? jonas.thornvall@gmail.com - 2015-09-27 09:02 -0700

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