Skip to content

    TFPSListCompareFunc

    Compare list items callback signature.

    Declaration

    Source position: fgl.pp line 45

    type
  TFPSListCompareFunc = function(Key1: Pointer; Key2: Pointer) : Integer
                                of object;

    Arguments

    Name Description
    Key1 First key value.
    Key2 Second key value.

    Function result

    Is key1 less than key2.

    Description

    TFPSListCompareFunc is used in the TFPSList.Sort method to compare 2 elements. The list passes 2 pointers to the actual items to the compare function. The result of this function determines how the pointers will be sorted:

    • If the result of this function is negative, the first key (key1) is assumed to be 'less' than the second key (key2) and will be moved before the second in the list.
    • If the function result is positive, the first key (key1) pointer is assumed to be 'greater than' the second key (key2)and will be moved after the second in the list.
    • if the function result is zero, the keys are assumed to be 'equal' and no moving will take place.

    See also

    Name Description
    TFPSList.Sort Sort the list.