Non repeating random numbers in iOS? [duplicate]

Answer 1

Hope the below lines of code will help you

srand(time(NULL));
int randomIndex = rand() % limit;
[reportIDTextField setText:[NSString stringWithFormat:@"%i", randomIndex]];

Benefit of this code is it won't allow repetitive random numbers. Here limit for random numbers.

Hope this is what you are looking for.

Enjoy Coding :)

Answer 2

    NSMutableArray *storeArray = [[NSMutableArray alloc] init];    
    BOOL record = NO;
    int x;

    for (int i=0; [storeArray count] < 10; i++) //Loop for generate different random values
    {
        x = arc4random() % 10;//generating random number
        if(i==0)//for first time 
        {
          [storeArray addObject:[NSNumber numberWithInt:x]];  
        }
        else
        {
            for (int j=0; j<= [storeArray count]-1; j++) 
            {
                    if (x ==[[storeArray objectAtIndex:j] intValue]) 
                    record = YES;
            }

            if (record == YES) 
            {
                record = NO;
            }
            else
            {
                [storeArray addObject:[NSNumber numberWithInt:x]];
            }
        }
    }
    NSLog(@" Non Repeated Random Numbers : %@",storeArray);

can u try this code may be it's use full to you

Answer 3

int n = 10;
NSMutableArray *numbers = [NSMutableArray array];
for (int i = 0; i <= n; i++) {
    [numbers addObject:[NSNumber numberWithInt:i]];
}
NSMutableArray *result = [NSMutableArray array];
while ([numbers count] > 0) {
    int r = arc4random() % [numbers count];
    NSNumber *randomElement = [numbers objectAtIndex:r];
    [result addObject:randomElement];
    [numbers removeObjectAtIndex:r];
}
NSLog(@"%@", result);

Answer 4

srand(time(NULL));
 int s[10];
 BOOL fl = 1;
for (int i = 0; i<10; i++) {
   while (fl) {
      s[i] = rand()%10;
      fl = 0;
      for (int j = 0; j < i; j++) {
         if (s[j] == s[i]) {fl = 1; j = i+1;}
      }
   }
}

Answer 5

You can do something like this

number = (arc4random()%10)+1; //Generates Number from 1 to 10.

save it to an Array Then you can put a condition,That will check the number whether it is present or not in the array. if not then add it to the array ,if it is already present then simply discard it.

A NOTE: "Never, ever add or multiply random numbers in an attempt to get 'better' randomness :)

Answer 6

Try this:- This will produce numbers between 0 to 10 randomly.

 srand(time(NULL));
int n = 11;
int card[n];  
for (int y=0; y<n; y++) {
    card[y] = y;  
}
for(int q= 0 ;q<3;q++) { 
    for (int y=0; y<(n-1); y++) {
        int r = y + (arc4random() % (n-y));         
        int temp = card[y]; card[y] = card[r]; card[r] = temp;
    }
}
for (int g=0;g<n ; g++) {
    int w = card[g];
    NSLog(@"%i",w);
}