Code - Custom Function
cfGetEveryNthValue ( pList ; pStart ; pIncrement ; pInputSeparator ; pOutputSeparator )
BrianDunning.com, Brian Dunning http://www.briandunning.com/filemaker-custom-functions/list.php
cfGetEveryNthValue ( pList ; pStart ; pIncrement ; pInputSeparator ; pOutputSeparator )
Rate this function: Average rating: 5.0 (1 vote) Discuss this Custom FunctionKevin Frank, Kevin Frank & Associates
http://www.kevinfrank.com
Extract every Nth item from a list; allow starting value and list separators to be specified
==================== SAMPLE INPUT AND OUTPUT ====================
INPUT
cfGetEveryNthValue ( "A~B~C~D~E~F" ; 2 ; 3 ; "~" ; "$" )
OUTPUT
B$E
==================== DESCRIPTION ====================
Recently I needed to reduce a list to "every other" item in that list, i.e., the 1st item, the 3rd item, the 5th item, etc.
It occurred to me that in the future I might need, say, every third item rather than every other item, and that I might want to begin with something other than the first item on the list. It also occurred to me that I might want to specify a list separator other than a hard return, for either the input, the output, or both.
That's how this CF came to be.
==================== CUSTOM FUNCTION ====================
/*
Purpose: Extract every Nth item from a list; allow starting value and list separators to be specified
Author: Kevin Frank & Associates (www.kevinfrank.com)
Usage: cfGetEveryNthValue ( pList ; pStart ; pIncrement ; pInputSeparator ; pOutputSeparator )
Example:
cfGetEveryNthValue ( "A~B~C~D~E~F" ; 2 ; 3 ; "~" ; "$" ) = "B$E"
Note: if you leave pInputSeparator and/or pOutputSeparator blank, ¶ will be used, e.g.,
cfGetEveryNthValue ( "A¶B¶C¶D¶E¶F" ; 1 ; 2 ; "" ; "" ) = "A¶C¶E"
*/
Let ( [
theInputSeparator = If ( IsEmpty ( pInputSeparator ) ; ¶ ; pInputSeparator ) ;
theOutputSeparator = If ( IsEmpty ( pOutputSeparator ) ; ¶ ; pOutputSeparator ) ;
theList = If ( theInputSeparator <> ¶ ; Substitute ( pList ; theInputSeparator ; ¶ ) ; pList )
] ;
GetValue ( theList ; pStart ) &
If (
ValueCount ( theList ) >= ( pStart + pIncrement ) ;
theOutputSeparator & cfGetEveryNthValue ( pList ; pStart + pIncrement ; pIncrement ; pInputSeparator ; pOutputSeparator )
)
) // end let
Rate this function: Average rating: 5.0 (1 vote) Discuss this Custom FunctionKevin Frank, Kevin Frank & Associates
http://www.kevinfrank.com
Extract every Nth item from a list; allow starting value and list separators to be specified
==================== SAMPLE INPUT AND OUTPUT ====================
INPUT
cfGetEveryNthValue ( "A~B~C~D~E~F" ; 2 ; 3 ; "~" ; "$" )
OUTPUT
B$E
==================== DESCRIPTION ====================
Recently I needed to reduce a list to "every other" item in that list, i.e., the 1st item, the 3rd item, the 5th item, etc.
It occurred to me that in the future I might need, say, every third item rather than every other item, and that I might want to begin with something other than the first item on the list. It also occurred to me that I might want to specify a list separator other than a hard return, for either the input, the output, or both.
That's how this CF came to be.
==================== CUSTOM FUNCTION ====================
/*
Purpose: Extract every Nth item from a list; allow starting value and list separators to be specified
Author: Kevin Frank & Associates (www.kevinfrank.com)
Usage: cfGetEveryNthValue ( pList ; pStart ; pIncrement ; pInputSeparator ; pOutputSeparator )
Example:
cfGetEveryNthValue ( "A~B~C~D~E~F" ; 2 ; 3 ; "~" ; "$" ) = "B$E"
Note: if you leave pInputSeparator and/or pOutputSeparator blank, ¶ will be used, e.g.,
cfGetEveryNthValue ( "A¶B¶C¶D¶E¶F" ; 1 ; 2 ; "" ; "" ) = "A¶C¶E"
*/
Let ( [
theInputSeparator = If ( IsEmpty ( pInputSeparator ) ; ¶ ; pInputSeparator ) ;
theOutputSeparator = If ( IsEmpty ( pOutputSeparator ) ; ¶ ; pOutputSeparator ) ;
theList = If ( theInputSeparator <> ¶ ; Substitute ( pList ; theInputSeparator ; ¶ ) ; pList )
] ;
GetValue ( theList ; pStart ) &
If (
ValueCount ( theList ) >= ( pStart + pIncrement ) ;
theOutputSeparator & cfGetEveryNthValue ( pList ; pStart + pIncrement ; pIncrement ; pInputSeparator ; pOutputSeparator )
)
) // end let
Referring URL: 'http://www.briandunning.com/cf/1118'
Keywords: ''
ClipManager:
