Last Updated: February 25, 2016

Split a CamelCase string into separate words

Objective: Split a CameCase string such as `iLikeNames' into separate words ("I Like Names").

So I was looking for a way to do this online but found nothing. There was some recommendations on using regex to do it but I thought that was way to messy for such a simple tasks.

Therefore I spent some time writing my own implementation and this is what I came up with. It is tested and passed all my tests. Although the code is a bit long but it gets the job done. There might be a cleaner way to do this so any suggestions are welcome:

This is to be used as a category for NSString.

- (NSString *)splitOnCapital
{
 // Make a index of uppercase characters
 NSRange upcaseRange = NSMakeRange('A', 26);
 NSIndexSet *upcaseSet = [NSIndexSet indexSetWithIndexesInRange:upcaseRange];

 // Split our camecase word
 NSMutableString *result = [NSMutableString string];
 NSMutableString *oneWord = [NSMutableString string];
 for (int i = 0; i < self.length; i++) {
 char oneChar = [self characterAtIndex:i];
 if ([upcaseSet containsIndex:oneChar]) {
 // Found a uppercase char, now save previous word
 if (result.length == 0) {
 // First word, no space in beginning
 [result appendFormat:@"%@", [oneWord capitalizedString]];
 }else {
 [result appendFormat:@" %@", oneWord];
 }

 // Clear previous word for new word
 oneWord = [NSMutableString string];
 }

 [oneWord appendFormat:@"%c", oneChar];
 }

 // Add last word
 if (oneWord.length > 0) {
 [result appendFormat:@" %@", oneWord];
 }

 return result;
}

#cocoa

#nsstring

#objective-c