NSString과 const char* 간 서로 컨버팅

먼저 Objective-C의 NSString -> C의 const char*

NSString *str = @"String object to a C string";

const char *ptr = [str cStringUsingEncoding:NSUTF8StringEncoding];

또는

const char* prt2 = [str UTF8String];

둘의 차이는 아직 자세히는...

const char* -> NSString

ptr = "C string to string object";

str = [NSString stringWithUTF8String:ptr];

또는

str = [NSString stringWithCString:ptr encoding:NSUTF8StringEncoding];

입니다.

NSString.h에 Encoding enum이 많이 있네요.

enum {

    NSASCIIStringEncoding = 1, /* 0..127 only */

    NSNEXTSTEPStringEncoding = 2,

    NSJapaneseEUCStringEncoding = 3,

    NSUTF8StringEncoding = 4,

    NSISOLatin1StringEncoding = 5,

    NSSymbolStringEncoding = 6,

    NSNonLossyASCIIStringEncoding = 7,

    NSShiftJISStringEncoding = 8,          /* kCFStringEncodingDOSJapanese */

    NSISOLatin2StringEncoding = 9,

    NSUnicodeStringEncoding = 10,

    NSWindowsCP1251StringEncoding = 11,    /* Cyrillic; same as AdobeStandardCyrillic */

    NSWindowsCP1252StringEncoding = 12,    /* WinLatin1 */

    NSWindowsCP1253StringEncoding = 13,    /* Greek */

    NSWindowsCP1254StringEncoding = 14,    /* Turkish */

    NSWindowsCP1250StringEncoding = 15,    /* WinLatin2 */

    NSISO2022JPStringEncoding = 21,        /* ISO 2022 Japanese encoding for e-mail */

    NSMacOSRomanStringEncoding = 30,

    NSUTF16StringEncoding = NSUnicodeStringEncoding,      /* An alias for NSUnicodeStringEncoding */

    NSUTF16BigEndianStringEncoding = 0x90000100,          /* NSUTF16StringEncoding encoding with explicit endianness specified */

    NSUTF16LittleEndianStringEncoding = 0x94000100,       /* NSUTF16StringEncoding encoding with explicit endianness specified */

    NSUTF32StringEncoding = 0x8c000100,                   

    NSUTF32BigEndianStringEncoding = 0x98000100,          /* NSUTF32StringEncoding encoding with explicit endianness specified */

    NSUTF32LittleEndianStringEncoding = 0x9c000100        /* NSUTF32StringEncoding encoding with explicit endianness specified */

};