copy与retain的区别：
1)copy是创建一个新对象，retain是创建一个指针，引用对象计数加1。Copy属性表示两个对象内容相同，新的对象retain为1 ，与旧有对象的引用计数无关，旧有对象没有变化。copy减少对象对上下文的依赖。
2)retain属性表示两个对象地址相同（建立一个指针，指针拷贝），内容当然相同，这个对象的retain值+1也就是说，retain 是指针拷贝，copy 是内容拷贝。
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#pragma mark - iOS系统的集合类与非集合类的retain和copy // 非容器类（NSString / NSNumber等）
NSString *str1 = [[NSString alloc] initWithFormat:@"%@", @"Jacedy"];
NSString *str11 = [str1 retain];
NSString *str12 = [str1 copy];
NSString *str13 = [str1 mutableCopy];
NSMutableString *str2 = [[NSMutableString alloc] initWithString:@"Jake"];
NSMutableString *str21 = [str2 retain];
NSMutableString *str22 = [str2 copy];
NSMutableString *str23 = [str2 mutableCopy];
NSLog(@"非容器类");
NSLog(@"str1 的地址：%p，retainCount：%lu", str1, (unsigned long)[str1 retainCount]);
NSLog(@"str11的地址：%p，retainCount：%lu", str11, (unsigned long)[str11 retainCount]);
NSLog(@"str12的地址：%p，retainCount：%lu", str12, (unsigned long)[str12 retainCount]);
NSLog(@"str13的地址：%p，retainCount：%lu\n\n", str13, (unsigned long)[str13 retainCount]);
NSLog(@"str2 的地址：%p，retainCount：%lu", str2, (unsigned long)[str2 retainCount]);
NSLog(@"str21的地址：%p，retainCount：%lu", str21, (unsigned long)[str21 retainCount]);
NSLog(@"str22的地址：%p，retainCount：%lu", str22, (unsigned long)[str22 retainCount]);
NSLog(@"str23的地址：%p，retainCount：%lu\n\n", str23, (unsigned long)[str23 retainCount]);
// 容器类（集合类）（NSArray / NSSet等）
NSArray *arr1 = [NSArray arrayWithObjects:@"one", @"two", nil];
NSArray *arr11 = [arr1 retain];
NSArray *arr12 = [arr1 copy];
NSArray *arr13 = [arr1 mutableCopy];
NSMutableArray *arr2 = [NSMutableArray arrayWithObjects:@"one", @"two", nil];
NSMutableArray *arr21 = [arr2 retain];
NSMutableArray *arr22 = [arr2 copy];
NSMutableArray *arr23 = [arr2 mutableCopy];
NSLog(@"容器类");
NSLog(@"arr1 的地址：%p，retainCount：%lu", arr1, (unsigned long)[arr1 retainCount]);
NSLog(@"arr11的地址：%p，retainCount：%lu", arr11, (unsigned long)[arr11 retainCount]);
NSLog(@"arr12的地址：%p，retainCount：%lu", arr12, (unsigned long)[arr12 retainCount]);
NSLog(@"arr13的地址：%p，retainCount：%lu", arr13, (unsigned long)[arr13 retainCount]);
NSLog(@"arr1[0] :%p", arr1[0]);
NSLog(@"arr13[0]:%p\n\n", arr13[0]);
NSLog(@"arr2 的地址：%p，retainCount：%lu", arr2, (unsigned long)[arr2 retainCount]);
NSLog(@"arr21的地址：%p，retainCount：%lu", arr21, (unsigned long)[arr21 retainCount]);
NSLog(@"arr22的地址：%p，retainCount：%lu", arr22, (unsigned long)[arr22 retainCount]);
NSLog(@"arr23的地址：%p，retainCount：%lu", arr23, (unsigned long)[arr23 retainCount]);
NSLog(@"arr2[0] :%p", arr2[0]);
NSLog(@"arr22[0]:%p\n\n", arr22[0]);
#pragma mark - NSString 内存管理 NSString *string1 = @"Jacedy";
NSString *string2 = [[NSString alloc] initWithString:@"KJacedy"];
NSString *string3 = [[NSString alloc] initWithFormat:@"Jacedy"];
NSString *string4 = [NSString stringWithFormat:@"K-Jacedy"];
//NSString *string5 = [NSString stringWithString:@"Jacedy"]; //该方法等同于string1
NSLog(@"NSString内存管理");
NSLog(@"string1:%p retainCount:%lu class:%@", string1, [string1 retainCount], [string1 class]);
NSLog(@"string2:%p retainCount:%lu class:%@", string2, [string2 retainCount], [string2 class]);
NSLog(@"string3:%p retainCount:%lu class:%@", string3, [string3 retainCount], [string3 class]);
NSLog(@"string4:%p retainCount:%lu class:%@\n\n", string4, [string4 retainCount], [string4 class]);
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// 输出结果：非容器类str1 的地址：0x79646563614a65，retainCount：18446744073709551615str11的地址：0x79646563614a65，retainCount：18446744073709551615str12的地址：0x79646563614a65，retainCount：18446744073709551615str13的地址：0x100203a70，retainCount：1str2 的地址：0x100203f20，retainCount：2str21的地址：0x100203f20，retainCount：2str22的地址：0x656b614a45，retainCount：18446744073709551615str23的地址：0x100204040，retainCount：1容器类arr1 的地址：0x100300a90，retainCount：3arr11的地址：0x100300a90，retainCount：3arr12的地址：0x100300a90，retainCount：3arr13的地址：0x100301190，retainCount：1arr1[0] :0x1000021b0arr13[0]:0x1000021b0arr2 的地址：0x100301260，retainCount：2arr21的地址：0x100301260，retainCount：2arr22的地址：0x100301370，retainCount：1arr23的地址：0x100301390，retainCount：1arr2[0] :0x1000021b0arr22[0]:0x1000021b0NSString内存管理string1:0x100002050 retainCount:18446744073709551615 class:__NSCFConstantString
string2:0x100002390 retainCount:18446744073709551615 class:__NSCFConstantString
string3:0x79646563614a65 retainCount:18446744073709551615 class:NSTaggedPointerString
string4:0xd2eec83802a585 retainCount:18446744073709551615 class:NSTaggedPointerString
Program ended with exit code: 0
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深拷贝与浅拷贝结论：
1)对非集合类：
[immutableObject copy] // 浅复制
[immutableObject mutableCopy] //深复制
[mutableObject copy] //深复制
[mutableObject mutableCopy] //深复制
2)对集合类：
[immutableObject copy] // 浅复制
[immutableObject mutableCopy] //单层深复制（即仅对对象本身进行深复制，对象元素仍是浅复制（指针拷贝，内存地址不变））
[mutableObject copy] //单层深复制
[mutableObject mutableCopy] //单层深复制
NSString内存分配结论：
@“” 和 initWithString：方法生成的字符串分配在常量区，系统自动管理内存；
initWithFormat：和 stringWithFormat: 方法生成的字符串分配在堆区，autorelease