我试图做一个包含5个实例变量的行星对象的mutableCopy（其中之一是一个字符串文字的NSMutableArray。我的问题是，我不确定如何将newPlanet>数据设置为self> data的副本，有道理？ 
 
-(id) mutableCopyWithZone: (NSZone *) zone {
    Planet *newPlanet = [[Planet allocWithZone:zone] init];
    NSLog(@"_mutableCopy: %@", [newPlanet self]);
    [newPlanet setName:name];
    [newPlanet setType:type];
    [newPlanet setMass:mass];
    [newPlanet setIndex:index];

    // NSMutableArray *data; HOW TO: newPlanet>data = self>data? 

    return(newPlanet);
}
 
 EDIT_001： 
 
 基于Chuck＆bbum的评论，我更新了我的方法并添加了以下内容...... 
 
@property(retain) NSMutableArray *data;
@synthesize data;
 
 。 
 
-(id) mutableCopyWithZone: (NSZone *) zone {
    Planet *newPlanet = [[Planet allocWithZone:zone] init];
    NSLog(@"_mutableCopy: %@", [newPlanet self]);
    [newPlanet setName:name];
    [newPlanet setType:type];
    [newPlanet setMass:mass];
    [newPlanet setIndex:index];

    NSMutableArray *copiedArray = [[self data] mutableCopyWithZone:zone];
    [newPlanet setData: copiedArray];
    [copiedArray release];

    return(newPlanet);
}
 
 非常感激 
 
 加里 

I a trying to make a mutableCopy of a planet object that contains 5 instance variables (one of them being an NSMutableArray of string literals. My problem is that I am unsure how to set the newPlanet>data to a copy of self>data, does that make sense?
 
-(id) mutableCopyWithZone: (NSZone *) zone {
    Planet *newPlanet = [[Planet allocWithZone:zone] init];
    NSLog(@"_mutableCopy: %@", [newPlanet self]);
    [newPlanet setName:name];
    [newPlanet setType:type];
    [newPlanet setMass:mass];
    [newPlanet setIndex:index];

    // NSMutableArray *data; HOW TO: newPlanet>data = self>data? 

    return(newPlanet);
}
 
EDIT_001:
 
Based on the comments by Chuck & bbum I updated my method and added the following ...
 
@property(retain) NSMutableArray *data;
@synthesize data;
 
.
 
-(id) mutableCopyWithZone: (NSZone *) zone {
    Planet *newPlanet = [[Planet allocWithZone:zone] init];
    NSLog(@"_mutableCopy: %@", [newPlanet self]);
    [newPlanet setName:name];
    [newPlanet setType:type];
    [newPlanet setMass:mass];
    [newPlanet setIndex:index];

    NSMutableArray *copiedArray = [[self data] mutableCopyWithZone:zone];
    [newPlanet setData: copiedArray];
    [copiedArray release];

    return(newPlanet);
}
 
much appreciated
 
gary

原文：https://stackoverflow.com/questions/2015943