Creating a random number

**Wiretron** · 11-20-2006

I need to create a random integer between 0 and 255, what function would I use and how would I accomplish this?

**vart** · 11-20-2006

rand()%256

**Wiretron** · 11-20-2006

Also, how can I cast this number to a char?

**manutd** · 11-20-2006

Code:

char thechar[3];
int num = rand()%256;
itoa(num, thechar, 10);            //Note that this is not ANSI standard C.

EDIT:Not a cast, but a function.

**Wiretron** · 11-20-2006

Ah ok thanks.

**Wiretron** · 11-20-2006

My compiler didn't like itoa at all, are there any alternatives I can use?

**Happy_Reaper** · 11-20-2006

I particularly don't see the problem with casting your number to a char, so long as it's between 0 and 255.

**Wiretron** · 11-20-2006

Yes but how do I do it?

**Happy_Reaper** · 11-20-2006

Code:

int d = 65;
char c = (char)d;

Voila.

In fact, I remember somewhere reading that you should keep chars in ints anyways...but I don't know if that's accurate at all.

**Wiretron** · 11-20-2006

Ah cheers.

**manutd** · 11-20-2006

Code:

char thechar[3];
int num = rand()%256;
sprintf(thechar, "%d", num);

**Wiretron** · 11-20-2006

I'm having a problem with the the random function. It's not very random.

Everytime I run the program, it is picking the same numbers.

**manutd** · 11-20-2006

Seed rand:

Code:

srand(time(NULL));

**vart** · 11-20-2006

You should call it once - for example in the beginning of main

**Wiretron** · 11-20-2006

I get this message:

warning: implicit declaration of function ‘time’

Thread: Creating a random number