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Re: End of selected items.

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On 11.11.19 11:52, Jonas Thörnvall wrote:

> An array can hold elements with different types, there is no problem to step thru all elements of an array.
> 
> But how do one handle stepping thru an array where you do not know the last element of a certain type?
> 
> What is the condition for the increment->, that tells this was the last element?

You step thru the whole array and just use the element if it is of a
certain type and ignore the others.

> You can't tell it was the last element until end of array? Should one just scroll thru and find last element index of each type and save at beginning?

Yes.

> I guess that must be done but am not sure, this problem must come up in every database?

In a database one would just not query element types you don't want.

For example with an SQL query:

select * from articles where location='bookshelf'

and NOT:

"select * from articles" followed by a script which goes thru the result
just to find the last article with the condition "location=='bookshelf'".


-- 
Arno Welzel
https://arnowelzel.de

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Thread

End of selected items. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2019-11-11 02:52 -0800
  Re: End of selected items. John G Harris <niam@jghnorth.org.uk.invalid> - 2019-11-11 11:22 +0000
    Re: End of selected items. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2019-11-11 05:58 -0800
  Re: End of selected items. Arno Welzel <usenet@arnowelzel.de> - 2019-11-12 15:31 +0100
    Re: End of selected items. "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2019-11-12 15:46 +0100

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