Swap array objects

//When clicking button it change different

- (IBAction)click:(id)sender {

    /*[ar replaceObjectAtIndex:0 withObject:[ar objectAtIndex:2]];

    [ar replaceObjectAtIndex:1 withObject:[ar objectAtIndex:0]];

    [ar replaceObjectAtIndex:2 withObject:[ar objectAtIndex:1]];

    */

    NSUInteger count = [ar count];

    for (NSUInteger i = 0; i < count; ++i) {

        int nElements = count - i;

        int n = (arc4random() % nElements) + i;

        [ar exchangeObjectAtIndex:i withObjectAtIndex:n];

        

    }

    t1.text=[ar objectAtIndex:0];

    t2.text=[ar objectAtIndex:1];

    t3.text=[ar objectAtIndex:2];

}