osx - How to keep track of a class's objects in Objective C -

i'm new c , objective-c, , implement class method return nsdictionary of objects meeting criteria, such starred articles in example:

article.h:

@interface article : nsobject {     nsstring *title;     bool starred; } ... + (nsmutabledictionary*) starredarticles; @end 

how approach this? static global nsmutablearray inside article.m file, insert/delete in constructor , destructor?

this isn't way go--there must object containing articles in application. that's object should return starred articles--this class method might seem idea now, it's inflexible.

so, have object storing articles in nsmutablearray. use predicate (see the predicate programming guide) find starred articles , return desired dictionary.