select a random button from array - ios

Question

I have to hide one of mine four UIButtons, randomly selected, BUT Excepting one.
for this, I created a NSMutableArray, and added all button there, as following example:
rand_btns = [[NSMutableArray alloc] initWithObjects: _bt1, _bt2, _bt3, _bt4,nil];
No, each button has its own tag: _bt1 has tag 1, _bt2 has tag 2, and so...
Please, any ideas? I want to hide one random button, but excepting a button which has tag equal to my: int Level.
I want to use this for a Quiz App.
So, my int Level is from 1-4 random number, when one of mine four buttons has tag equal to mine int Level, that button should be excepted from hiding.

Answer 1

Try this
-(void)randomSelForLevel:(NSInteger)level
{
int randomTag = rand() % 4;
while (randomTag == level) {
randomTag = rand() % 4;
}
for (int i=0; i<[rand_btns count]; i++) {
[[rand_btns objectAtIndex:randomTag] setHidden:NO];
}
[[rand_btns objectAtIndex:randomTag] setHidden:YES];
}

Answer 2

Just do this.
int randomTag = rand() % 4;
while (randomTag == Level) {
randomTag = rand() % 4;
}
[[randButtons objectAtIndex:randomTag] setHidden:YES]

Answer 3

to select random no between two no use this code:
int random = lowno + arc4random() % (highno-lowno);
Thanks.

Answer 4

abarr = [[NSMutableArray alloc]init];
for (int i = 0; i < 5; i++){
ab = [[UIButton alloc]init];
ab = [UIButton buttonWithType:UIButtonTypeRoundedRect];
ab.tag = i;
[ab setTitle:[NSString stringWithFormat:#"%ld",ab.tag] forState:UIControlStateNormal];
[ab addTarget:self action:#selector(clicked:) forControlEvents:UIControlEventTouchUpInside];
[ab sizeToFit];
ab.backgroundColor = [UIColor yellowColor];
[abarr addObject:ab];
[self.view addSubview:ab];
switch (ab.tag) {
case 0:
ab.frame=CGRectMake(0, 0, 50,50);
break;
case 1:
ab.frame=CGRectMake(50, 0, 50,50);
break;
case 2:
ab.frame=CGRectMake(100, 0, 50,50);
break;
case 3:
ab.frame=CGRectMake(150, 0, 50,50);
break;
default:
break;
}
}
randomTag = rand() % 4;
for (int i=0; i<[abarr count]; i++) {
[[abarr objectAtIndex:randomTag] setBackgroundColor:[UIColor redColor]];
}
[[abarr objectAtIndex:randomTag] setBackgroundColor:[UIColor redColor]];
}
-(void)clicked:(UIButton*)button
{
NSLog(#"%ld",(long int)[button tag]);
for (int i=0; i<[abarr count]; i++)
{
[[abarr objectAtIndex:randomTag] setHidden:YES];
}
}