| Description |
The Boolean type provides an enumeration of the logical True and False values.
Unlike other languages, it is not a number - it will only allow these values. This makes the code much more reliable.
|
|
| Notes |
Using calculations to test for true or false is a C like practice, but is supported in Delphi. Use the following to hold such a logical number:
ByteBool
WordBool
LongBool
|
|
| Related commands |
| And |
|
Boolean and or bitwise and of two arguments |
| If |
|
Starts a conditional expression to determine what to do next |
| Not |
|
Boolean Not or bitwise not of one arguments |
| Or |
|
Boolean or or bitwise or of two arguments |
| Xor |
|
Boolean Xor or bitwise Xor of two arguments |
|
|
|
|
|
| Example code : Boolean assignments and tests |
var
same : Boolean;
small, large, i : Integer;
begin
small := 23;
large := 455555;
// Test directly to see if these numbers are the same size
if small = large
then WriteLn('small = large')
else WriteLn('small <> large');
// Use a Boolean to hold and test this outcome
same := (small = large);
if same
then WriteLn('small = large')
else WriteLn('small <> large');
// Assign a direct logical value to this Boolean
same := True;
if same
then WriteLn('same is True')
else WriteLn('same is False');
end;
|
| Show full unit code |
small <> large
small <> large
same is True
|
|