iphone - How to manage memory management in iOS -

i need clarification memory management concepts.

i declare 1 variable in .h

    @interface rootviewcontroller : uiviewcontroller     {          nsmutablearray *objmutablearray;     }     @property (nonatomic,retain)   nsmutablearray *objmutablearray; 

in .m file

    @implementation rootviewcontroller      @synthesize objmutablearray=_objmutablearray;      - (void)viewdidload     {          [super viewdidload];           self.objmutablearray=[[nsmutablearray alloc]init];          [self.objmutablearray addobject:@"firstrow"];         [self.objmutablearray addobject:@"secondrow"];         [self.objmutablearray addobject:@"thirdrow"];         [self.objmutablearray addobject:@"fourthrow"];         [self.objmutablearray addobject:@"fifthrow"];     } 

i used self.objmutablearray places. when release memory instance used _objmutablearray.

    - (void)dealloc     {          [_objmutablearray release];          [super dealloc];     } 

actually confused when release memory instance. please tell me did correct or must release "objmutablearray" object.

you seem using manual memory management , not arc. fine, got wrong.

please tell me did correct or must release "objmutablearray" object.

of course have release because created using alloc. how did not correct. leaking memory because in viewdidunload method (i suppose should viewdidload instead, shouldn't it!?) assigning retain property - object have reference count of 2 (one because of + alloc, 1 because of (retain)).

now when releasing in - dealloc, still have reference count of one, class doesn't dispose of ownership, hence memory leak.

solution:

you can use either property or instance variable. don't mix two. approach #1:

_objmutablearray = [[nsmutablearray alloc] init];  // ...  [_objmutablearray release]; 

approach #2:

self.objmutablearray = [[[nsmutablearray alloc] init] autorelease];  // ...  self.objmutablearray = nil;