Choose — Caution
IMO the documentation is slightly faulty in its example for the “integer” use
of this command.
The issue is that Choose returns the “null” value for the type being used if
the integer value is not in the range covered.
From the Documentation
* * * * * * * * * * * * * * * *
* * * * *
Example 2
Here is an example of the typical use of this command with a Number type
criterion:
vStatus:=Choose([Person]Status;"Single";"Married";"Widowed";"Divorced")
This code is strictly equivalent to:
Case of
:([Person]Status=0)
vStatus:="Single"
:([Person]Status=1)
vStatus:="Married"
:([Person]Status=2)
vStatus:="Widowed"
:([Person]Status=3)
vStatus:="Divorced"
End case
* * * * * * * * * * * * * * * *
* * *
This is not "strictly" correct. You need to add an Else to the Case statement
to get complete equivalency
The null value of the type (in this case "") is returned if the integer value
is out of range (in this case the range is 0-3)
Case of
:([Person]Status=0)
vStatus:="Single"
:([Person]Status=1)
vStatus:="Married"
:([Person]Status=2)
vStatus:="Widowed"
:([Person]Status=3)
vStatus:="Divorced"
Else
vStatus:=""
End case
So if vStatus had some other value going into the Choose statement, it is going
to loose that value even if there was no matching criteria.
> On Jul 6, 2017, at 9:45 AM, Chip Scheide via 4D_Tech <4d_tech@lists.4d.com>
> wrote:
>
> I found out about a command I had not known about
> Choose
>
> I love this command
> if anyone does not know about it - read it is so nice to do in one
> line of code what other wee takes at least5
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