ListGetFirst Function

Action

Returns a copy of the first element of a list.

Include file

List.bdh

Syntax

ListGetFirst(
   in theList: list,
   inout retElement: union) : boolean;

Parameter	Description
theList	List of number, boolean, float or string.
retElement	Number, boolean, float or string, which contains a copy of the first element of theList as an out parameter. Has to conform with the type of theList.

Return value

true if successful
false otherwise

Example

transaction TAListGetFirst
var
  lstNumber: list of number init 10, 20, 30;
  numberElem: number;
  stringElem: string;   
  retVal: boolean; 
begin
  retVal := ListGetFirst(lstNumber, numberElem);
  if((retVal = true) and (numberElem = 10)) then
    writeln("ListGetFirst worked! Value of numberElem: " + string(numberElem));
  end;
  retVal := ListGetFirst(lstNumber, stringElem);
  if(retVal = false) then
    writeln("ListGetFirst did not work, the types do not match!"); 
  end;
end TAListGetFirst;

Output

ListGetFirst worked! Value of numberElem: 10
ListGetFirst did not work, the types do not match!