Question

NSMutableArray * arrayTest;

-(void) setContent
{
  //must I call [array removeAllObjects]; ? 
  arrayTest = [[NSMutableArray alloc] init]

  [arrayTest addObject:@"str"];
  ...//add many objects
}

I call this function at different code snippet. do I need to removeAllObjects of arrayTest before , then alloc memory for arrayTest every time ? I use ARC .
I don’t want my app memory to increase every time I call this function.

Answer 1

No, what you have is fine. You don’t need to call removeAllObjects under ARC or non-ARC.

When the old array is deallocated, it will take care of releasing all of the objects in the old array.