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There are 2,577 functions in this library.

LuhnDoubleEven ( makeEven )

Part of the Luhn function

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Geoff Wells
DataIsland Software LLC
http://www.dataisland.com

Sample input:

NA - called internally by Luhn

Sample output:

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

/* 
A component of the Luhn function.


Take the number string supplied by Luhn and double every even position character of the original number.
Adding 0 to the front of odd length number strings adjusted the original number for this to work.
*/

If ( Length ( makeEven )  > 1 ; 2 * Middle(makeEven ; 1; 1) & Middle(makeEven ; 2; 1) & LuhnDoubleEven ( Right ( makeEven; Length ( makeEven ) - 2 ) )
 ; "" )

One of two additional functions that must be defined before Luhn

Comments

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