Generating a Random value in objective-c

Hi, today lets see how to generate a random number from zero to a given Number.

/ Get random value between 0 and 99
int x = arc4random() % 100;
 
// Get random number between 500 and 1000
int y =  (arc4random() % 501) + 500); 

Now Lets see how to Generate a random alpha numeric value.  This is usually required for genrating passwords/ IDs.

   NSString *letters = @"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

-(NSString *) genRandStringLength: (int) len {

    NSMutableString *randomString = [NSMutableString stringWithCapacity: len];

    for (int i=0; i<len; i++) {
         [randomString appendFormat: @"%C", [letters characterAtIndex: arc4random() % [letters length]]];
    }

    return randomString;
}