如何将一个NSString从CamelCase转换为TitleCase,'playerName'转换为'Player Name'？

Question

我正在寻找将字符串从驼峰格式转换为标题案例格式的最简单方法.

如何将"playerName"更改为"玩家姓名"？

Answer 1

NSString *str = @"playerName";
NSMutableString *str2 = [NSMutableString string];

for (NSInteger i=0; i<str.length; i++){
    NSString *ch = [str substringWithRange:NSMakeRange(i, 1)];
    if ([ch rangeOfCharacterFromSet:[NSCharacterSet uppercaseLetterCharacterSet]].location != NSNotFound) {
        [str2 appendString:@" "];
    }
    [str2 appendString:ch];
}
NSLog(@"%@", str2.capitalizedString);

Answer 2

这是一个更简单的Swift版本.我把它扔进了一个扩展名

extension String {

    func stringFromCamelCase() -> String {
        var string = self
        string = string.stringByReplacingOccurrencesOfString("([a-z])([A-Z])", withString: "$1 $2", options: NSStringCompareOptions.RegularExpressionSearch, range: Range<String.Index>(start: string.startIndex, end: string.endIndex))
        string.replaceRange(startIndex...startIndex, with: String(self[startIndex]).capitalizedString)
        return string
    }

}

用法:

var str = "helloWorld"
str = str.stringFromCamelCase()

Answer 3

尝试使用正则表达式替换

NSString *modified = [input stringByReplacingOccurrencesOfString:@"([a-z])([A-Z])"
                                                      withString:@"$1 $2"
                                                         options:NSRegularExpressionSearch
                                                           range:NSMakeRange(0, input.length)];

Answer 4

使用NSCharacterSet稍短一些:

__block NSString *str = @"myVerySpecialPlayerName" ;

// split at uppercase letters
NSArray *splitString = [str componentsSeparatedByCharactersInSet:
     [NSCharacterSet uppercaseLetterCharacterSet]] ;

// get the uppercase letters
NSArray *upperCaseLetters = [str componentsSeparatedByCharactersInSet:
     [[NSCharacterSet uppercaseLetterCharacterSet] invertedSet]] ;

// join with two spaces
str = [splitString componentsJoinedByString:@"  "] ;
__block NSInteger offset = 0 ;

// replace each second space with the missing uppercase letter
[upperCaseLetters enumerateObjectsUsingBlock:^(NSString *character, NSUInteger idx, BOOL *stop) {
    if( [character length] > 0 ) {
        str = [str stringByReplacingCharactersInRange:NSMakeRange(idx+offset+1, 1) withString:character] ;
        offset += 2 ;
    }
}] ;

// & capitalize the first one
str = [str capitalizedString] ;

NSLog(@"%@", str) ; // "My Very Special Player Name"