ObjectPascal Pred Function Decrement an ordinal variable System unit

function Pred ( const Ordinal Value ) : Ordinal type;

Description The Pred function decrements an ordinal value, and returns this value.   You can decrement :   Characters  Non-floating number types  Enumeration types  Pointers    The decrement is by the base size of the unit. For example, decrementing a Pointer will be by 2 bytes if the pointer points to Words.   Notes Pred is equivalent in performance to simple subtraction, or the Dec procedure. Related commands Dec Decrement an ordinal variable Inc Increment an ordinal variable Sqr Gives the square of a number Sqrt Gives the square root of a number Succ Increment an ordinal variable Sum Return the sum of an array of floating point values		Example code : Decrementing characters, numbers and enumerations type   TSuit = (Hearts, Clubs, Diamonds, Spades); var   Character : char;   Number    : Integer;   Card      : TSuit; begin   // We can decrement characters   Character := 'B';   WriteLn('Character : '+Character);   Character := Pred(Character);   WriteLn('Character-1 : '+Character);   // We can decrement numbers   Number := 23;   WriteLn('Number : '+IntToStr(Number));   Number := Pred(Number);   WriteLn('Number-1 : '+IntToStr(Number));   // We can decrement enumerations   Card := Clubs;   WriteLn('Card starts at Clubs');   Card := Pred(Card);   if Card = Hearts then WriteLn('Card is now Hearts');   if Card = Clubs then WriteLn('Card is now Clubs');   if Card = Diamonds then WriteLn('Card is now Diamonds');   if Card = Spades then WriteLn('Card is now Spades'); end; Show full unit code    Character : B    Character-1 : A    Number : 23    Number-1 : 22    Card starts at Clubs    Card is now Hearts