（转）【iOS 开发】二进制、十进制、十六进制相互转换的方法-白红宇

下面罗列了二进制、十进制、十六进制之间相互转换的方法，有时候可能会用的到，需要的朋友可以收藏一下。

###1. 十进制转换为二进制

/**  十进制转换为二进制  @param decimal 十进制数  @return 二进制数  */ + (NSString *)getBinaryByDecimal:(NSInteger)decimal {
       NSString *binary = @"";     while (decimal) {
           binary = [[NSString stringWithFormat:@"%ld", decimal % 2] stringByAppendingString:binary];         if (decimal / 2 < 1) {
               break;         }         decimal = decimal / 2 ;     }     if (binary.length % 4 != 0) {
           NSMutableString *mStr = [[NSMutableString alloc]init];;         for (int i = 0; i < 4 - binary.length % 4; i++) {
               [mStr appendString:@"0"];         }         binary = [mStr stringByAppendingString:binary];     }     return binary; } 复制代码

###2. 十进制转换为十六进制

/** 十进制转换十六进制 @param decimal 十进制数 @return 十六进制数 */+ (NSString *)getHexByDecimal:(NSInteger)decimal {    NSString *hex =@"";    NSString *letter;    NSInteger number;    for (int i = 0; i<9; i++) {        number = decimal % 16;        decimal = decimal / 16;        switch (number) {            case 10:                letter =@"A"; break;            case 11:                letter =@"B"; break;            case 12:                letter =@"C"; break;            case 13:                letter =@"D"; break;            case 14:                letter =@"E"; break;            case 15:                letter =@"F"; break;            default:                letter = [NSString stringWithFormat:@"%ld", number];        }        hex = [letter stringByAppendingString:hex];        if (decimal == 0) {            break;        }    }    return hex;}复制代码

###3. 二进制转换为十六进制

/** 二进制转换成十六进制 @param binary 二进制数 @return 十六进制数 */+ (NSString *)getHexByBinary:(NSString *)binary {    NSMutableDictionary *binaryDic = [[NSMutableDictionary alloc] initWithCapacity:16];    [binaryDic setObject:@"0" forKey:@"0000"];    [binaryDic setObject:@"1" forKey:@"0001"];    [binaryDic setObject:@"2" forKey:@"0010"];    [binaryDic setObject:@"3" forKey:@"0011"];    [binaryDic setObject:@"4" forKey:@"0100"];    [binaryDic setObject:@"5" forKey:@"0101"];    [binaryDic setObject:@"6" forKey:@"0110"];    [binaryDic setObject:@"7" forKey:@"0111"];    [binaryDic setObject:@"8" forKey:@"1000"];    [binaryDic setObject:@"9" forKey:@"1001"];    [binaryDic setObject:@"A" forKey:@"1010"];    [binaryDic setObject:@"B" forKey:@"1011"];    [binaryDic setObject:@"C" forKey:@"1100"];    [binaryDic setObject:@"D" forKey:@"1101"];    [binaryDic setObject:@"E" forKey:@"1110"];    [binaryDic setObject:@"F" forKey:@"1111"];    if (binary.length % 4 != 0) {        NSMutableString *mStr = [[NSMutableString alloc]init];;        for (int i = 0; i < 4 - binary.length % 4; i++) {            [mStr appendString:@"0"];        }        binary = [mStr stringByAppendingString:binary];    }    NSString *hex = @"";    for (int i=0; i

###4. 十六进制转换为二进制

/** 十六进制转换为二进制 @param hex 十六进制数 @return 二进制数 */+ (NSString *)getBinaryByHex:(NSString *)hex {    NSMutableDictionary *hexDic = [[NSMutableDictionary alloc] initWithCapacity:16];    [hexDic setObject:@"0000" forKey:@"0"];    [hexDic setObject:@"0001" forKey:@"1"];    [hexDic setObject:@"0010" forKey:@"2"];    [hexDic setObject:@"0011" forKey:@"3"];    [hexDic setObject:@"0100" forKey:@"4"];    [hexDic setObject:@"0101" forKey:@"5"];    [hexDic setObject:@"0110" forKey:@"6"];    [hexDic setObject:@"0111" forKey:@"7"];    [hexDic setObject:@"1000" forKey:@"8"];    [hexDic setObject:@"1001" forKey:@"9"];    [hexDic setObject:@"1010" forKey:@"A"];    [hexDic setObject:@"1011" forKey:@"B"];    [hexDic setObject:@"1100" forKey:@"C"];    [hexDic setObject:@"1101" forKey:@"D"];    [hexDic setObject:@"1110" forKey:@"E"];    [hexDic setObject:@"1111" forKey:@"F"];    NSString *binary = @"";    for (int i=0; i<[hex length]; i++) {        NSString *key = [hex substringWithRange:NSMakeRange(i, 1)];        NSString *value = [hexDic objectForKey:key.uppercaseString];        if (value) {            binary = [binary stringByAppendingString:value];        }    }    return binary;}复制代码

###5. 二进制转换为十进制

/** 二进制转换为十进制 @param binary 二进制数 @return 十进制数 */+ (NSInteger)getDecimalByBinary:(NSString *)binary {    NSInteger decimal = 0;    for (int i=0; i

大概就这么多了，有其他需求可以补充，需要十六进制转换为十进制的话，就按上面方法将十六进制转换为二进制后再转换为十进制就行了，有需要的朋友就收藏一下吧！

http://www.jianshu.com/p/126ebfbd460e