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POSetter for NSString, how is it working?
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  1. POSetter for NSString, how is it working?
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    copied!<p>This question follows on from a previous question, that has raised a further issue. What I am trying to understand is just when the pointers and object in this example are being created and what ultimately happens to them. I am still trying to get my head round this, so please excuse any false assumptions I may have made.</p> <pre><code>// MAIN int main (int argc, const char * argv[]) { PlanetClass *newPlanet_01 = [[PlanetClass alloc] init]; [newPlanet_01 setGeekName:@"StarWars"]; } </code></pre> <p>.</p> <pre><code>// CLASS @interface PlanetClass : NSObject { NSString *geekName; } - (NSString*) geekName; - (void) setGeekName:(NSString*)gName; @end </code></pre> <p>.</p> <pre><code>// SETTER - (void)setGeekName:(NSString *)gName { if (geekName != gName) { [geekName release]; geekName = [gName copy]; } } </code></pre> <p>(A) ... When an instance of PlanetClass "newPlanet_01" is first created is the NSString instance variable object created, or just a pointer to a possible future object? If it is just a pointer what am I releasing later in the setter as its just a pointer, not a pointer to an object?</p> <p>(B) ... In the above example "gName" is a pointer to the NSString object @"StarWars"?</p> <p>(C) ... Next is the pointer geekName different from the gName (i.e. if geekName does not already point at @"StarWars")</p> <p>(D) ... geekName release, what is released the first time the code is run, my understanding was that geekName is just a pointer to does not point to anything. Or does release just not release anything this first time?</p> <p>(E) ... Finally geekName = [gName copy]; the newly released geekName is now assigned to point to a <em>copy</em> of gName, what happens to the original gName?</p>
 

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