Simple C question for you coding freaks!

ManWithThePlan

lads i've just finished my first project of the year but i'm stuck on one thing.
im coding in C, and i just need a random integer between 15 and 25 to be generated.

i've tried:
num1 = randomInteger(10) + 15;

it should work but i'm getting an error on that line - unrsolved symbol blah blah

would apreciate the help lads
cheers

Peace

post your code.....

Mutant_Fruit

Here's code to generate A random number, but not within the range you want.

Its up to you to figure out how thats done. Also, this is probably quite a complicated way of doing it, there are probably easier ways i don't know of

#include <stdio.h>
#include <stdlib.h>

int randomInteger(int n)
{
  return rand() % n;
}

int main()
{
  int i = 0;
  while (i < 10)
    {
      printf("%d\n", randomInteger(600));
      i++;
    }
  return 0;
}

jessy

Why are you writting a function that's only functionality is to call another function???

aidan_walsh

jessy wrote:

Why are you writting a function that's only functionality is to call another function???

Because its good practise to keep individual functionality in individual methods?

jessy

doodle_sketch wrote:

Because its good practise to keep individual functionality in individual methods?

I dont understand your answer. what other functionality can rand() have? and if it is the case why is the printf() not been called from another function?

Random

// random number between 1 and 100
randNumber = (rand() % 100) +1;

aidan_walsh

Yeah, ok, fair point. In this case it was unnecessary... I didn't look at the code properly and thought there was more going on...

rob1891

don't forget to seed your random number, otherwise it is not going to be very random!

#include <stdlib.h>
#include <time.h>

....

srand(time(NULL));

....


If you don't do this, your program will be using the same random number every time you run it ... :eek:

Magnolia_Fan

I study C and I didn't understand a word you guys typed!...I've got a problem with an assignment I might be back to yee before the end of the week...cheers lol

Mr.StRiPe

#include <stdlib.h>


int num1 = (rand() % 11) +15;

//(rand() % 11) will return a random num between 0 - 10
//Therefore adding 15 to it will give you a num between 15 - 25

ManWithThePlan

cheers lads i used a combination of a few answers and i got it!

Cheers again!!

Mutant_Fruit

jessy wrote:

Why are you writting a function that's only functionality is to call another function???

Because i like things complicated. Plus, its the way i was shown how to do it before

Anyway, glad to see you figured out a working answer.Tis why we're here!

jessy

Mutant_Fruit wrote:

Because i like things complicated. Plus, its the way i was shown how to do it before

Anyway, glad to see you figured out a working answer.Tis why we're here!

Im all for High Coupling And Low Cohesion but thats a bit extream putting standard llibrary functions in other functions just to call them. still ya had the right answer(apart from seeding it):)

fatherdougalmag

You obviously haven't had the joy making a Windows driver WHQL/HCT compliant. There's a nice money-spinner for the boys at Microsoft.

There's a particular test called the Kernel Calls test. The idea is that depending on your driver, you're only allowed to call certain functions in the kernel. In the days of NT you pretty much used the ntoskrnl and co. for doing your stuff. Then for Windows 2000 and on they insisted you use, for example, NDIS.SYS (networking) for doing your stuff. Hook up your debugger and step into an NdisXXXX routine - hey presto - it just calls the fecking NTOSKRNL equiv which you previously called in your driver. But if you submit your driver ($$$$) and fail you've got to resubmit (more $$$).

So there's you spending mundo dosh on a graphics adapter and during the driver installation a dialog pops up informing you that Microsoft haven't verified the driver. What do you do? Click cancel and feck the whole lot in the bin? I don't think so. That's the most hated dialog in our lives. The hours and hours of testing that need to go into just having that silly little dialog not pop up during your driver install. You should see some of the lengths some driver providers go to to auto-click it away. Madness.

Microsfoft, Ted. Shower of bastards.