objective c - Quick NSMutableArray Question -

i wondering, using nsmutablearray best way making array adding objects to? or, regular nsarray? secondly, i'm trying make sort of arraylist in java (so there no limit size), , know how that. i've thought of make bigger array , copy older array it. code:

- (void) addaccount:(bankaccount *)b {  accountcount = [nsnumber numberwithdouble:[accountcount doublevalue] + 1];     nsmutablearray *oldlist = accounts; accounts = [[nsmutablearray alloc] (some code make bigger , copy over)];  } 

p.s. taught myself language yesterday, may not understand response if it's advanced

nsmutablearrays want. also, nsmutablearrays arraylists or stl vectors, or else "no limit size". can [myarray addobject:someobject]; until run out of memory, , keep resizing needed.