Randomizing Alert view text for Objective C - objective-c

Question

I am new to programming. I am having trouble finding out what all is wrong with this. It is an alert view that i am trying to randomize the text displayed in the message.
-(void)alert:(id)sender{
int randomNumber;
randomNumber = (randomNumber() %3 + 1);
NSLog(#"%i", randomNumber);
if (randomNumber == 1) {
self.YouWin.text = [NSString stringWithFormat:#"You Win"];
}
else if (randomNumber == 2) {
self.YouWin.text = [NSString stringWithFormat:#"You Lose"];
}
else if (randomNumber == 3) {
self.YouWin.text = [NSString stringWithFormat:#"Tie"];
}
NSLog(#"%#",YouWin);
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello" message:[NSString stringWithFormat:#"%#",YouWin] delegate:self cancelButtonTitle:#"Ok" otherButtonTitles: nil];
[alert show];
button.hidden = YES;

Answer 1

Try this one:
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:self.YouWin.text
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
You needed text-value stored in YouWin, but you passed the YouWin object itself.
*Note: you can use arc4random() for generating random numbers.

Answer 2

There are many good suggestions; I agree with AKB8085.
Replacing the randomNumber() with arc4random() will help at compile time.
But you might want to re-think implementing a random number generator. The reason is in fairness to your user. I pose the question, “Is it fair to assume you want your user to guess a number with this large of a number range?”
Did you Know?
Using the arc4random(3), rand(3), or random(3) you are using a C function.
You are asking the user to guess a number with the following ranges:
arc4random(3) = 0 to 4294967296
rand(3) and random(3) that top out at a RAND_MAX of 0x7fffffff (214748647)
To help in answering your question, answer the following requirement questions:
Is there a min/max range restraint?
What type of compelling delays will happen
by using arc4random(3), rand(3), or random(3)?
Is using NSArray like in the Fisher–Yates_shuffle a better answer?
SUGGESTION:
Read an article on random numbers and NSArray.
NOTE:
Random numbers tend to task the compiler and your user experience will be hindered.

Answer 3

As Anoop noted you are using stringWithFormat but you're not providing a format string at all.
You should do
[NSString stringWithFormat:#"%#", #"You Win"];
but that's extremely redundant, although correct, and it's totally equivalent to just using #"You Win".
Also an advice for the general approach on the problem. Instead of having a big if-else statement, it's better to store all your string into a data structure and then randomly access to it.
In code this would translate to
NSArray * outcomes = #[ #"You Win", #"You lose", #"Tie" ];
int randomIndex = arc4random_uniform(outcomes.count);
NSString * randomOutcome = outcomes[randomIndex];
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:randomOutcome
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
button.hidden = YES;
Note the usage of arc4random_uniform() that gives you back a random number between 0 and the argument provided, excluded.

Answer 4

Replace
randomNumber = (randomNumber() %3 + 1);
with
randomNumber = arc4random() %3 + 1;
Also use this...
if (randomNumber == 1) {
self.YouWin.text = [NSString stringWithFormat:#"You Win"];
}
else if (randomNumber == 2) {
self.YouWin.text = [NSString stringWithFormat:#"You Lose"];
}
else if (randomNumber == 3) {
self.YouWin.text = [NSString stringWithFormat:#"Tie"];
}
NSLog(#"%#",YouWin);
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:self.YouWin.text
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
button.hidden = YES;