false and true
From Free Pascal wiki
│
English (en) │
The constant false
is used to define the false condition of a boolean
variable, as opposed to its opposite, true
.
This is a manifest constant which is defined as part of the standard data types the compiler initially knows about.
This constant value must be predefined by the compiler as there is no way to define it in terms of anything else.
program falseDemo(input, output, stderr);
uses
typInfo;
begin
writeLn(false); // prints FALSE
// enumerative actions ------------------------------------------
writeLn(ord(false)); // prints 0
writeLn(succ(false)); // prints TRUE
// next two statements generate out-of-range compile-time warnings
writeLn(pred(false)); // prints TRUE
writeLn(succ(succ(false))); // prints TRUE
// data type ----------------------------------------------------
writeLn(sizeOf(false)); // prints 1
writeLn(bitSizeOf(false)); // prints 8
writeLn(PTypeInfo(typeInfo(false))^.kind); // prints tkBool
writeLn(PTypeInfo(typeInfo(false))^.name); // prints Boolean
end.