Random non repeat number Xcode
===

Sorry for my bad English, I'm argentinian. I have a question, I am makin a trivia application and logically it doesn't have to re-ask the same. I have 30 questions and this is my code:`-(IBAction)randomear{
    
    random1=arc4random() % 30;
    
    if (random1 == 0)
    {
        labelpregunta.text = @"Las ovejas pueden nadar?";
    }
    
    if (random1 == 1)
    {
        labelpregunta.text = @"Con que se tiñe la lana de negro?";
    }
    
    if (random1 == 2)
    {
        labelpregunta.text = @"De que material es el mejor casco?";
    }
    
    if (random1 == 3)
    {
        labelpregunta.text = @"Para fabricar lana necesitas 4 _____";
    }

`
I want to create an NSArray where, if there are a number who repeats, it shuffle again.

I need the code for this, because I'm a beginner.

PD: I know that so much if's is idiot but I like it. 