DelphiBasics
 RandomFunction Generate a random floating point or integer number System unit
 1 function Random():Extended; 2 function Random (LimitPlusOne Integer:Integer;
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.
Related commands
 Randomize Reposition the Random number generator next value RandomRange Generate a random integer number within a supplied range RandSeed Reposition the Random number generator next value

 Example code : Generate sets of floating point and integer numbers 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; Show 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