You are right - it doesn't work because here:
if (randomValue==oldquest[j])
you are trying to compare an int with an object... NSArrays can only store objects. In fact this line should not work for that reason:
[oldquest addObject: randomValue];
You need to box the int as an NSNumber and store that in the array:
NSNumber* boxedRandomValue = [NSNumber numberWithInt:randomValue];
[oldquest addObject: boxedRandomValue];
Then unbox it using the NSNumber instance method -(int)intValue before comparing values:
if (randomValue==[oldquest[j] intValue])
update
There are a few other issues you will have to attend to:
the value of kk is reset to 1 on each iteration of the test, so kk == 1 is always true, the else clause is never invoked. You need to set it once only outside of this block of code (for example you could make it a property, set it to 1 on initialise, then access and increment it here). Better still, just use [oldquest count] instead: if ([oldquest count]==0) {} else {}. Then you can dispense with your kk counter altogether.
your for-loop starts with j=1. This should be j=0 to address the first item in the array (item 0).
update 2
This line: randomValue = (arc4random() % numerodomande)+ 1 is going to cause all sort of other problems due to it's position in the checking loop. Try one of these suggestions:
just return when you come across a dupe. No number gets added to the array...
set a BOOL test inside the loop, deal with it outside:
BOOL repeatedValue = NO;
for (int j=0; j<[self.oldquest count]; j++){
if (randomValue==[self.oldquest[j] intValue]) {
repeatedValue = YES;
break;
}
}
if (repeatedValue){
NSLog (@"value repeated");
[self addRandom];
//recursive call to this code block,
//assuming it is a method called `addRandom`
}
Try a compact version of the last suggestion (similar to Odrakir's solution) - I've enclosed it in an addRandom method so you can see how to call it recursively.
- (void) addRandom {
int numberofquest = 5;
int randomValue = (arc4random() % numberofquest)+ 1;
NSNumber* boxedValue = [NSNumber numberWithInt:randomValue];
if ([self.oldquest indexOfObject:boxedValue]==NSNotFound) {
[self.oldquest addObject: boxedValue];
} else {
[self addRandom];
}
}
(If you do loop until you find a unique number you will have to watch out, as your total set of numbers is finitely limited to numberofquest, so when you have a full set you may end up with an infinite loop.)
Instead of using NSMutableArray, you could use MutableOrderedSet instead - it's an ordered collection of unique objects, so will not add an object twice.
in @interface
@property (nonatomic, strong) NSMutableOrderedSet setOfRandoms;
in @implementation
int randomValue = (arc4random() % numberofquest)+ 1;
NSNumber randomValueBoxed = [NSNumber numberWithInt:randomValue];
[setOfRandoms addObject:randomValueBoxed];
update 3
The previous hints assumed it was the list of randoms you were interested in. Here is a complete solution to return a new unique random int in a self-contained method.
You need to set up 2 properties in your @interface and initialise them somewhere:
@property (nonatomic, assign) int maxRand;
//stores the highest allowed random number
@property (nonatomic, strong) NSMutableArray* oldRands;
//stores the previously generated numbers
uniqueRandom returns a unique random number between 1 and self.maxRand each time. If all allowable numbers have been returned it returns 0.
- (int) uniqueRandom {
int result = 0;
if ([self.oldRands count] != self.maxRand) {
int randomValue = (arc4random() % self.maxRand )+ 1;
NSNumber* boxedValue = [NSNumber numberWithInt:randomValue];
if ([self.oldRands indexOfObject:boxedValue]==NSNotFound) {
[self.oldRands addObject: boxedValue];
result = randomValue;
} else {
result = [self uniqueRandom];
}
}
return result;
}
You should consider that it doesn't make sense to change self.maxRand once it is initialised unless you also reset self.oldRands. So you might want to use a const or #define instead, and/or tie it in to your self.oldRands initialiser.
