| Description |
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The RandSeed variable is used in conjunction with the Random function. It changes the seed used that Delphi uses to generate its range of 232 pseudo random numbers.
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| Related commands |
| Random |
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Generate a random floating point or integer number |
| 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 |
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| Example code : Run this code twice to see the effect of RandSeed |
// 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
int : Integer;
i : Integer;
hours, mins, secs, milliSecs : Word;
begin
// Get random numbers using the default random seed value
ShowMessage('Fixed first 5 random numbers');
for i := 1 to 5 do
begin
int := 1 + Random(100); // The 100 value gives a range 0..99
ShowMessage('int = '+IntToStr(int));
end;
// Now change the random seed to the milliseconds value
// of the current time
DecodeTime(now, hours, mins, secs, milliSecs);
ShowMessage('');
ShowMessage('Setting randSeed to value : '+IntToStr(milliSecs));
ShowMessage('');
RandSeed := milliSecs;
// Get an integer random number in the range 1..100
ShowMessage('Random next 5 numbers');
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 |
Fixed first 5 random numbers
int = 1
int = 4
int = 87
int = 21
int = 28
Setting random seed to value : 660
Random next 5 numbers
int = 72
int = 62
int = 28
int = 63
int = 44
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