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-   -   Print out Prime Numbers (http://www.daniweb.com/code/snippet138.html)

vegaseat qbasic syntax
Jan 1st, 2005
I just had to do this to see how it would look like in the code field. This small prime number generator is written in BCX basic, a mildy more modern basic than Qbasic. With BCX basic you can throw in C and assembler code and it would actually compile it. Gives you the familiar comfort of basic, but allows you to venture to C at will. 

  1. ' look at a series of numbers and print out the prime numbers
  2. ' prime numbers are divisible only by unity or themselves
  3. ' this is BCX basic, a modern successor to Qbasic
  4.  
  5. DIM A    ' defaults to integer
  6.  
  7. FOR A = 1 TO 100
  8.   IF IsPrime(A) THEN PRINT A;
  9. NEXT
  10.  
  11. Pause   ' make console wait
  12.  
  13. FUNCTION IsPrime(Num)
  14.   LOCAL X
  15.   ' make exeptions for unity and 2
  16.   IF Num = 1 THEN FUNCTION = True
  17.   IF Num = 2 THEN FUNCTION = True
  18.   ' leave on even numbers
  19.   IF MOD(Num, 2) = 0 THEN EXIT FUNCTION
  20.   FOR X = 3 TO Num - 1 STEP 2
  21.     IF MOD(Num, X) = 0 THEN EXIT FUNCTION
  22.   NEXT X
  23.   FUNCTION = TRUE  ' return true if it's a Prime Number
  24. END FUNCTION