How to declare a C array property in objective-c

Question

How to declare a C array of integers as a property on an objective-c class?

http://stackoverflow.com/questions/912016/declaring-properties-synthesizing-and-implementing-int-array-in-objective-c — CoolMonster, Feb 20 '14 at 12:51
http://stackoverflow.com/questions/476843/create-an-array-of-integers-property-in-objective-c — Rushabh, Feb 20 '14 at 13:01
Please see my updated answer. stack based arrays will probably get cleaned after the method call. Happy coding :) — Basheer_CAD, Feb 20 '14 at 13:12

Basheer_CAD · Accepted Answer · 2014-02-20T13:10:50.050

6

@property (nonatomic, assign) int *array;
...
// somewhere in your code 
    int *gg = malloc(10 * sizeof(int));
    gg[1] = 1;
    gg[0] = 2;
    self.array = gg;

UPDATE:

This is heap based array now to make sure it will not be deallocated.
But don't forget to free it in dealloc free(self.array)

edited Feb 20 '14 at 13:10

answered Feb 20 '14 at 12:55

Basheer_CAD

4,858
23
36

exactly what i was trying to achieve. the cleanest answer from all in other similar questions – Nicolas Manzini Feb 20 '14 at 12:57
great :)@NicolasManzini – Basheer_CAD Feb 20 '14 at 13:00
1

You can't do this. When you leave the scope where `gg` was declared your `array` property will contain pointer to a deallocated part of memory. Best case scenario you will get trash instead of values you want. In case of `int *array` array must be allocated on heap using `malloc` or `new`. – creker Feb 20 '14 at 13:06
@creker, yes you are right thank you. Updated my answer – Basheer_CAD Feb 20 '14 at 13:11
1

the funny thing is I was reading about this heap/stack problem right now! :) i can fill it with 0s by doing gg[] = {0} ? – Nicolas Manzini Feb 20 '14 at 13:20
yep :) thanks to @creker for reminding :) – Basheer_CAD Feb 20 '14 at 13:21

How to declare a C array property in objective-c

1 Answers1