FilterList ( beginsWith ; oldList ; newList ; iteration )

This recursive function will take a list and return a new list without list values that start with the supplied beginsWith string.

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Chris McCue
Chris McCue
http://www.imccue.com

Sample input:

FilterList ( "app" ; "apple¶application¶astro¶baseball" ; "" ; "" )

Sample output:

astro
baseball

Function definition: (Copy & paste into FileMaker's Edit Custom Function window)

// ===================================
/*

    Function Author: Chris McCue
    Bug Reporting: cmccue@mac.com
    Last updated: March 12, 2012
    Version: 1.0

    This recursive function will take a list and return a new list without
    list values that start with the supplied beginsWith string.

    FilterList ( beginsWith ; oldList ; newList ; iteration )
        Required Parameters: beginsWith ; oldList
        Optional Parameters: newList ; iteration

    Example: FilterList ( "app" ; "apple¶application¶astro¶baseball" ; "" ; "" )
    Returns: "astro¶baseball"

*/
// ===================================

Let ( [

		$c = ValueCount ( oldList ) ;
		$newlist = If ( IsEmpty ( newList ) ; "" ; newList ) ;
		$i = If ( IsEmpty ( iteration ) ; 1 ; iteration + 1 ) ;
		$length = Length ( beginsWith ) ;
		$val = GetValue ( oldList ; $i )

	] ;
	
	Case ( 
			$length = 0 or IsEmpty ( oldList ) ; "?" ;
			$i > $c ; newList ;
			beginsWith = Left ( $val ; $length ) ; FilterList ( beginsWith ; oldList ; newList ; $i ) ;
			Let ( newList = newList & $val & "¶" ; FilterList ( beginsWith ; oldList ; newList ; $i ) )
	)

)

This recursive function will take a list and return a new list without list values that start with the supplied beginsWith string.

Comments

		Lorne Walton, Maple Ridge, Canada Mar 12, 2012
Either the cf description is incorrect, or the example give the wrong result. The result should be: astro baseball

		Chris McCue, Dallas, TX Mar 12, 2012
Doh! Nice catch, thanks.

		Bart Bartholomay, Vero Beach Mar 13, 2012
I also think the description is misleading. You're filtering a list, ie you're return values that remain after applying the filter. Here you're taking them out. Why not call it: ContractList ( theList ; theValue ; theNewList ; theIteration ) Notice that I've reversed the first two and renamed the params for clarity.

		Davide puppo, CMI solutions srl Jun 16, 2018
A great variation is having the list with only the value that "begins with" change beginsWith = Left ( $val ; $length ) with beginsWith â‰ Left ( $val ; $length )

Note: these functions are not guaranteed or supported by BrianDunning.com. Please contact the individual developer with any questions or problems.

FilterList ( beginsWith ; oldList ; newList ; iteration )

Comments

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