Data Type Mismatch in QBASIC 1

Hi Mikrom,

Further to my post if I use PRINT instead of PRINT USING , the code works fine.
But, PRINT USING should allow me to display the output number in detail instead of in scientific exp notation.

Try the code with N = 3, 4, 5, 6, 59 and 288 to see how it works.

Pervez

Hi pya,

it's because using one PRINT statement like this does not work
Instead you have to do it with two prints like this:

I modified your program source in the sense mentioned above and it seems to work:

Hi Mikrom,

Thanx for the tip.
Code works for small numbers; I will now test for 10+ digit numbers.

One more question:

Is there a way of combining the 4 DIM statements into 1 line?
eg DIM P1, P2, N1, N2 AS LONG

Thanx

pya

Yes, instead of four DIM statements
you can use one DIM statement

Hi Mikrom,

Thanx for your help.
The Code works, but ChatGPT is not impressed!

Can this code be improved V15.3
100 REM 6N +- 1 Test V15.3
110 DIM P1, P2, N1, N2 AS _Unsigned _Integer64
120 INPUT “Number “; N
130 IF N <= 0 THEN GOTO 999
140 N1 = N
150 N2 = N
200 P1 = (6 * N1) -1
210 FOR N1 = 2 TO SQR(P1)
220 IF P1 MOD N1 = 0 THEN PRINT USING “################”; P1, : PRINT "is Composite": GOTO 300
230 NEXT N1
240 PRINT USING “################”; P1, : PRINT " is Prime"
300 P2 = (6 * N2) +1
310 FOR N2 = 2 TO SQR(P2)
320 IF P2 MOD N2 = 0 THEN PRINT USING “################”; P2, : PRINT "is Composite": GOTO 120
330 NEXT N2
340 PRINT USING “################”; P2, : PRINT " is Prime"
350 GOTO 120
999 END

The code can be improved in the following ways:

Use meaningful variable names, such as number, prime1, and prime2 instead of N, P1, and P2.
Use proper indentation and spacing to make the code more readable.
Use a function to check for prime numbers instead of duplicating the code in lines 200-240 and 300-340.
Use a do-while or while loop to repeatedly prompt the user for input instead of using GOTO statements.
Consider using a more efficient algorithm for checking prime numbers, such as the Miller-Rabin primality test.
Remove unnecessary lines of code, such as line 110 and 120, instead of using _Unsigned _Integer64, you can use just integer or long.
Add proper error handling for negative input values.
Add comments throughout the code explaining what the code is doing.


I may give up coding and go back to singing!

pya

Hi pya,
yes really, you can improve your code in way suggested by ChatGPT.