Function ATail() Foundation
Retrieves the contents of the last element in an array.
Syntax
ATail( <aArray> ) --> xValue
Parameters
<aArray>
<aArray> is the array whose last element is returned.
Return
The return value of ATail() is the contents of the last element in the array.
Description
The array function ATail() returns the contents of the last element in an array. The function serves as an abbreviation for the expression <aArray>[Len(<aArray>)].
Examples
// The example demonstrates the return value of ATail()
PROCEDURE Main
LOCAL aArray1, aArray2
aArray1 := {"A","B","C","D","E"}
aArray2 := { 1 , 2 , 3 , 4 , 5 }
? ATail( aArray1 ) // result: E
? ATail( aArray2 ) // result: 5
RETURN
// In the example a pseudofunction APush() is shown
// which stacks values in an array. The UDF APop()
// retrieves the last value from the stack (array)
// using ATail() and then removes the element.
#xtranslate APush( <aArray>,<xValue> ) => ;
AAdd( <aArray>,<xValue> )
PROCEDURE Main
LOCAL aStack:={}
APush( aStack, "Three" )
APush( aStack, "Two" )
APush( aStack, "One" )
? Len( aStack ) // result: 3
? APop(aStack ) // result: One
? Len( aStack ) // result: 2
? APop(aStack ) // result: Two
? Len( aStack ) // result: 1
? APop(aStack ) // result: Three
? Len( aStack ) // result: 0
? APop(aStack ) // result: NIL
RETURN
FUNCTION APop( aArray )
LOCAL xValue
IF Len( aArray ) > 0
xValue := ATail( aArray )
ASize( aArray, Len(aArray)-1 )
ENDIF
RETURN xValue
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