壹、屬性修飾符
讀寫屬性： （readwrite/readonly）
語義特性:(內存有關)：（assign/retain/copy）
原子特性:(和線程安全有關)： （atomicit/nonatomic）
readonly:只讀,屬性只會生成getter方法,不會生成setter.
readwrite:既可讀又可寫.屬性自動生成setter和getter方法.(默認的讀寫特性)
getter= 方法名:指定生成getter方法時的方法名.
setter= 方法名:指定生成setter方法時的方法名.
assign: 默認類型,setter方法直接賦值，而不進行retain操作,也可以只針對對象,只是做簡單的賦值操作. 默認的語義特性.
retain: 針對於對象類型，setter方法對參數進行release舊值，再retain新值。
copy: setter方法進行Copy操作，與retain壹樣, 針對於對象類型,會拷貝壹個新的對象,將新的對象的引用計數加1
nonatomic: 禁止多線程，變量保護，提高性能
atomic:原子特性,保證線程安全.系統默認的原子特性.
weak：指針指向的地址壹旦被釋放，這些指針都將被賦值為nil。這樣的好處能有效的防止野指針。消除循環引用 。
二、 @dynamic 關鍵字
@dynamic dynamicStr; // 告訴編譯器，不自定生成getter和setter方法，避免編譯期間產生警告，然後由自己實現存取方法。
三、 @synthesize 關鍵字
@synthesize strongStr = _strongStr; // 可以定義 與變量名不相同的getter和setter的命名,籍此來保護變量不會被不恰當的訪問, 編譯器期間，讓編譯器自動生成getter/setter方法 當有自定義的存或取方法時，自定義會屏蔽自動生成該方法
四、重定義setter方法getter方法
// 重定義setter方法
// 重定義getter方法
五、不可變字符串 NSString
// 運行log日誌：
2021-03-11 17:30:08.112340+0800 TestObject-C[93449:1623723] temp1: 不可變字符串, 0x10df9e778
2021-03-11 17:30:08.112529+0800 TestObject-C[93449:1623723] str: 不可變字符串, 0x10df9e778
2021-03-11 17:30:08.112610+0800 TestObject-C****[****93449:1623723****]**** strongStr: ****不可變字符串****, 0x10df9e778
六、可變字符串 NSMutableString
// 壹、將不可變字符串賦值給可變字符串對象。
// 賦值可變字符串對象後，對象仍然是不可變對象
2021-03-11 17:30:08.114159+0800 TestObject-C[93449:1623723] mTemp: 不 可變字符串1, 0x10df9e878
2021-03-11 17:30:08.114393+0800 TestObject-C[93449:1623723] mCopyStr: 不 可變字符串1, 0x10df9e878
2021-03-11 17:30:08.114697+0800 TestObject-C****[****93449:1623723****]**** mStrongStr: 不 可變字符串****1, 0x10df9e878
// 壹、將可變字符串賦值給可變字符串對象。
2021-03-11 19:38:34.493763+0800 TestObject-C[95274:1718783] mTemp2: 可變字符串2, 0x600002710ea0, __NSCFString
2021-03-11 19:38:34.493923+0800 TestObject-C[95274:1718783] mCopyStr: 可變字符串2, 0x6000027110e0, __NSCFString
2021-03-11 19:38:34.494037+0800 TestObject-C****[****95274:1718783****]**** mStrongStr: ****可變字符串****2, 0x600002710ea0, __NSCFString
2021-03-11 19:38:34.494422+0800 TestObject-C[95274:1718783] mTemp2: 可變字符串211, 0x600002710ea0, __NSCFString
2021-03-11 19:38:34.494697+0800 TestObject-C[95274:1718783] mCopyStr: 可變字符串2, 0x6000027110e0, __NSCFString
2021-03-11 19:38:34.494903+0800 TestObject-C****[****95274:1718783****]**** mStrongStr: ****可變字符串****211, 0x600002710ea0, __NSCFString
七、富文本字符串 NSMutableAttributedString
2021-03-11 19:34:52.041131+0800 TestObject-C[95207:1715249] attriStr: 我是富文本我是富文本我是富文本我是富文本, 0x600000a5bc00, NSConcreteMutableAttributedString
2021-03-11 19:34:52.041307+0800 TestObject-C[95207:1715249] mutableAttri: 我是富文本我是富文本我是富文本我是富文本, 0x600000a5be40, NSConcreteAttributedString
2021-03-11 19:34:52.041425+0800 TestObject-C****[****95207:1715249****]**** mutableStrongAttri: ****我是富文本我是富文本我是富文本我是富文本****, 0x600000a5bc00, NSConcreteMutableAttributedString
2021-03-11 19:34:52.041943+0800 TestObject-C[95207:1715249] attriStr: 我是富文本我是富文本我是富文本我是富文本---我是新添加的, 0x600000a5bc00, NSConcreteMutableAttributedString
2021-03-11 19:34:52.042281+0800 TestObject-C****[****95207:1715249****]**** mutableStrongAttri: ****我是富文本我是富文本我是富文本我是富文本****---****我是新添加的****, 0x600000a5bc00, NSConcreteMutableAttributedString
八、不可變數組NSArray
//壹、 不可變數組賦值NSArray的對象
2021-03-11 19:04:42.636207+0800 TestObject-C[94739:1689350] arr: (1, 2,
3), 0x600001d5c8d0
2021-03-11 19:04:42.636411+0800 TestObject-C[94739:1689350] persons: ( 1, 2, 3), 0x600001d5c8d0
2021-03-11 19:04:42.636538+0800 TestObject-C[94739:1689350] students: (1, 2, 3), 0x600001d5c8d0
2021-03-11 19:04:42.636646+0800 TestObject-C[94739:1689350] arr: (1, 2, 3), 0x600001d5c8d0
2021-03-11 19:04:42.636767+0800 TestObject-C[94739:1689350] students: (1, 2,3), 0x600001d5c8d0, __NSArrayI
// 二、不可變數組賦值給NSMutableArray的對象
**2021-03-11 19:15:59.046728+0800 TestObject-C[94934:1699039] arr: (1,2,3), 0x600002f6c000
2021-03-11 19:15:59.046878+0800 TestObject-C[94934:1699039] cars: (1, 2,3), 0x600002f6c000, __NSArrayI2021-03-11 19:15:59.046982+0800 TestObject-C[94934:1699039] dogs: (1,2,3), 0x600002f6c000, __NSArrayI
九、可變數組 NSMutableArray
2021-03-11 19:22:39.183745+0800 TestObject-C[95044:1705082] arr2: (2,4,10,12), 0x600000fefea0
2021-03-11 19:22:39.184067+0800 TestObject-C[95044:1705082] cars: (2,4,10), 0x600000fef240, __NSArrayI
**2021-03-11 19:22:39.184272+0800 TestObject-C[95044:1705082] dogs: (2,4,10,12), 0x600000fefea0, __NSArrayM
十、不可變字典 NSDictionary
// 不可變數組賦值給NSDictionary對象
2021-03-11 19:25:32.789615+0800 TestObject-C[95102:1708378] dic: {key1 = 1;key2 = value;}, 0x6000028799c0**
2021-03-11 19:25:32.789801+0800 TestObject-C[95102:1708378] personDic: { key1 = 1;key2 = value;}, 0x6000028799c0, __NSDictionaryI
2021-03-11 19:25:32.789919+0800 TestObject-C[95102:1708378] studentDic: { key1 = 1;key2 = value;}, 0x6000028799c0, __NSDictionaryI
十壹、可變字典 NSMutableDictionary
2021-03-11 19:59:28.739545+0800 TestObject-C[96373:1735182] mDic: { key1 = 10;key2 = value2;}, 0x6000017f0700, __NSDictionaryM
**2021-03-11 19:59:28.740177+0800 TestObject-C[96373:1735182] carDic: {key1 = 10;key2 = value2;}, 0x6000017f07a0, __NSFrozenDictionaryM
2021-03-11 19:59:28.740359+0800 TestObject-C[96373:1735182] dogDic: { key1 = 10;key2 = value2;}, 0x6000017f0700, __NSDictionaryM
2021-03-11 20:05:24.028840+0800 TestObject-C[96469:1740141] mDic: {key1 = 10; key2 = value2;key4 = value4;}, 0x6000011bd7e0, __NSDictionaryM
2021-03-11 20:05:24.028930+0800 TestObject-C[96469:1740141] carDic: { key1 = 10; key2 = value2;}, 0x6000011bd820, __NSFrozenDictionaryM
2021-03-11 20:05:24.029028+0800 TestObject-C[96469:1740141] dogDic: {key1 = 10;key2 = value2;key4 = value4;}, 0x6000011bd7e0, __NSDictionaryM
十二、不可變集合 NSSet
// 壹、不可變NSSet賦值給 NSSet對象
2021-03-11 20:09:49.418694+0800 TestObject-C[96545:1744249] set: {( 1,2,3)}, 0x600003fd2e80, __NSSetI
2021-03-11 20:09:49.418826+0800 TestObject-C[96545:1744249] personSet: {(1,2,3)}, 0x600003fd2e80, __NSSetI
2021-03-11 20:09:49.418914+0800 TestObject-C[96545:1744249] studentSet: {(1,2,3)}, 0x600003fd2e80, __NSSetI
// 二、不可變NSSet賦值給 NSMutableSet對象
2021-03-11 20:09:49.419281+0800 TestObject-C[96545:1744249] carSet: {(1,2,3)}, 0x600003fd2e80, __NSSetI
2021-03-11 20:09:49.419362+0800 TestObject-C[96545:1744249] dogSet: {(1, 2,3)}, 0x600003fd2e80, __NSSetI
十三、可變集合 NSMutableSet
2021-03-11 20:18:06.896997+0800 TestObject-C[96705:1752827] mSet: {(3,1,2,5)}, 0x600001e0a700, __NSSetM
2021-03-11 20:18:06.897218+0800 TestObject-C[96705:1752827] carSet: {( 1,2,3)}, 0x600001014bd0, __NSSetI
2021-03-11 20:18:06.897340+0800 TestObject-C[96705:1752827] dogSet: {(3,1,2, 5)}, 0x600001e0a700, __NSSetM