Prime number generation

[shekar.kr]

How to write a program for a prime number. If user gives 10, it should display all the prime numbers between 10.

 

[rusguy]

The simpliest method would be using division

DEFINE VARIABLE i AS INTEGER NO-UNDO.
[LEFT]DEFINE VARIABLE imax AS INTEGER INIT 100 NO-UNDO.
DEFINE VARIABLE imin AS INTEGER INIT 1 NO-UNDO.
DEFINE VARIABLE j AS INTEGER NO-UNDO.
DEFINE VARIABLE isPrime AS LOGICAL NO-UNDO.
REPEAT:
UPDATE imin imax.
DO i = imin TO imax WITH FRAME a:
  isPrime = TRUE.
  primeCheck:
  DO j = 2 TO SQRT(i):
    IF i MODULO j = 0 THEN
    DO:
      isPrime = FALSE.
      LEAVE primeCheck.
    END. 
  END.
  IF isPrime THEN
  DO:
    DISPLAY i WITH FRAME a.
    DOWN WITH FRAME a.
  END.
END.
END.[/LEFT]

 

[shekar.kr]

Thank u for providing me the logic. It is very useful for me.