NSMutableArray *experienceValues;
experienceValues = [NSMutableArray alloc] initWithObjects:0,83,174,276,nil];
NSLog(@"%@", [experienceValues objectAtIndex:3]);
Why does this always throw -[__NSArrayM objectAtIndex:]: index 3 beyond bounds for empty array when it is clearly allocated and initialised in the line just before?
The NSMutableArray class as most of the collection classes in cocoa, accepts only objects. So if you want to put numbers, you can't put primitive type, but only instances of NSNumber class, thus:
[[NSMutableArray alloc] initWithObjects:[NSNumber numberWithInt:0]...etc
Or with literals:
[[NSMutableArray alloc] initWithObjects:@0,@83,@174,@276.. etc
@0, @83 are "NSNumber literals". "Subscripting" is e.g. array[0] or dict[@"key"].The array is empty because the arguments are nil terminated and 0 is interpreted as nil.
The array should only contain objects (as opposed to primitives like ints). In you case you should create NSNumbers for all the numbers. You can do that with the number literal syntax @2.0.
Objective-C collection classes can only store objects; not primitives like int.
You need to wrap them in NSNumber objects.
If these are literal values then the answer provided by @Kirsteins demonstrates the syntax.
Try this
NSMutableArray *experienceValues = [[NSMutableArray alloc] initWithObjects:@0,@83,@174,@276,......., nil];
NSLog(@"%d", [experienceValues objectAtIndex:3]);
As initWithObjects: accepts only object you need to put only objects in it
You're trying to add integer value to NSArray.
NSMutableArray *experienceValues = [[NSMutableArray alloc] initWithObjects:[NSNumber numberWithInteger:42],nil];
then convert it back to integer like,
NSLog(@"%@", [experienceValues objectAtIndex:0]);
[on line 2 just before[NSMutableArray all..., and finally you need@before each integer.