NSString - Convert to pure alphabet only (i.e. remove accents+punctuation)

Question

I\'m trying to compare names without any punctuation, spaces, accents etc. At the moment I am doing the following:

-(NSString*) prepareString:(NSString*)a {
         


        

Answer 1

To give a complete example by combining the answers from Luiz and Peter, adding a few lines, you get the code below.

The code does the following:

1. Creates a set of accepted characters
2. Turn accented letters into normal letters
3. Remove characters not in the set

Objective-C

// The input text
NSString *text = @"BûvérÈ!@$&%^&(*^(_()-*/48";

// Create set of accepted characters
NSMutableCharacterSet *acceptedCharacters = [[NSMutableCharacterSet alloc] init];
[acceptedCharacters formUnionWithCharacterSet:[NSCharacterSet letterCharacterSet]];
[acceptedCharacters formUnionWithCharacterSet:[NSCharacterSet decimalDigitCharacterSet]];
[acceptedCharacters addCharactersInString:@" _-.!"];

// Turn accented letters into normal letters (optional)
NSData *sanitizedData = [text dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *sanitizedText = [NSString stringWithCString:[sanitizedData bytes] encoding:NSASCIIStringEncoding];

// Remove characters not in the set
NSString* output = [[sanitizedText componentsSeparatedByCharactersInSet:[acceptedCharacters invertedSet]] componentsJoinedByString:@""];

Swift (2.2) example

let text = "BûvérÈ!@$&%^&(*^(_()-*/48"

// Create set of accepted characters
let acceptedCharacters = NSMutableCharacterSet()
acceptedCharacters.formUnionWithCharacterSet(NSCharacterSet.letterCharacterSet())
acceptedCharacters.formUnionWithCharacterSet(NSCharacterSet.decimalDigitCharacterSet())
acceptedCharacters.addCharactersInString(" _-.!")

// Turn accented letters into normal letters (optional)
let sanitizedData = text.dataUsingEncoding(NSASCIIStringEncoding, allowLossyConversion: true)
let sanitizedText = String(data: sanitizedData!, encoding: NSASCIIStringEncoding)

// Remove characters not in the set
let components = sanitizedText!.componentsSeparatedByCharactersInSet(acceptedCharacters.invertedSet)
let output = components.joinWithSeparator("")

Output

The output for both examples would be: BuverE!_-48