how to use rand() in char

#1
iamanoob

Posted 02 November 2007 - 01:09 AM

Newbie

Members
6 posts

how to use rand() to get random char between A and Z;
and how to get random int between -9 to 9.

#2
Guest_Jordan_*

Posted 02 November 2007 - 03:45 AM

Guests

Do you want just A-Z capitalized or Aa-Zz? If you look at a ASCII chart you can see that A-Z is 65-90 so you need to generate a random number between those values:

*/ Declare our High and Low */
const int LOW = 65;
const int HIGH = 90;

*/ Char to hold our Ascii /*
char buffer [1];

*/ Seed the random number */
srand((unsigned int) seconds);

*/ Generate the number */
number = rand() % (HIGH - LOW + 1) + LOW;

*/ Convert to ASCII */
itoa (number,buffer,10);

With that code buffer will now hold your char. You could also just print it out with:

 printf("Ascii %s\n",  itoa(number, buffer, 10));

Moving this thread to the correct forum.

#3
gaffney2010

Posted 02 November 2007 - 01:26 PM

Newbie

Members
2 posts

That was a good explanation...

To get an integer between -9 and 9

int a=rand%19;   //random int between 0 and 18

a-=9;   //random int between -9 and 9

#4
iamanoob

Posted 02 November 2007 - 08:42 PM

Newbie

Members
6 posts

thx for help.. but Jordan can u pls try to make the code in one function, becasue i cant really understand what the code is...and how to use it...sry...

#5
iamanoob

Posted 02 November 2007 - 08:49 PM

Newbie

Members
6 posts

Jordan i try ur code, it can work but the result given is still a int value...and may i know what is this;

itoa (number,buffer,10);

#6
v0id

Posted 02 November 2007 - 11:58 PM

Retired

Members
2,936 posts

itoa is a non-standard function, and will not work right with all compilers. You can solve easily convert integers into characters by using a simple cast, like (char).

int GetRandom(int iMin, int iMax)
{
	return rand() % (iMax - iMin + 1) + iMin;
}

This is how your function should look like. As you see, it's actually just Jordan's code put into a function. You need to seed rand (srand) outside the function, right before you call it.