| Description |
The Random function generates random numbers. They can be floating point numbers in the range :
0 <= Number < 1.0
or integer numbers in the range :
0 <= Number < LimitPlusOne
Delphi uses a pseudo random number generator that always returns the same sequence of values (232) each time the program runs.
To avoid this predictability, use the Randomize procedure. It repositions into this random number sequence using the time of day as a pseudo random seed.
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| Related commands |
| Randomize |
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Reposition the Random number generator next value |
| RandomRange |
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Generate a random integer number within a supplied range |
| RandSeed |
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Reposition the Random number generator next value |
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| Example code : Generate sets of floating point and integer numbers |
// Full Unit code.
// -----------------------------------------------------------
// You must store this code in a unit called Unit1 with a form
// called Form1 that has an OnCreate event called FormCreate.
unit Unit1;
interface
uses
// The System unit does not need to be defined
SysUtils,
Forms, Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm} // Include form definitions
procedure TForm1.FormCreate(Sender: TObject);
var
float : single;
int : Integer;
i : Integer;
begin
// Get floating point random numbers in the range 0 <= Number < 1.0
for i := 1 to 5 do
begin
float := Random;
ShowMessage('float = '+FloatToStr(float));
end;
ShowMessage('');
// Get an integer random number in the range 1..100
for i := 1 to 5 do
begin
int := 1 + Random(100); // The 100 value gives a range 0..99
ShowMessage('int = '+IntToStr(int));
end;
end;
end.
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| Hide full unit code |
float = 2.3283064365387E-10
float = 0.031379981256104
float = 0.861048460006714
float = 0.202580958604813
float = 0.2729212641716
int = 68
int = 32
int = 17
int = 38
int = 43
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