NSString - Unicode to ASCII equivalent

Question

I need to convert NSString in unicode to NSString in ASCII changing all local characters: Ą to A, Ś to S, Ó to O, ü to u, And so on...

What is the simplest way to

Answer 1

Ken answer will replace "æ" with "ae" and "ß" with "s", but won't replace ligatures œ, ij, ff, fi, fl, ffi, ffl, ſt, st, ...

An improved solution is to first insert additional lines of mapping to handle everything fine:

string = [string stringByReplacingOccurrencesOfString:@"Œ" withString:@"OE"];
string = [string stringByReplacingOccurrencesOfString:@"œ" withString:@"oe"];
string = [string stringByReplacingOccurrencesOfString:@"Đ" withString:@"D"];
string = [string stringByReplacingOccurrencesOfString:@"đ" withString:@"d"];
string = [string precomposedStringWithCompatibilityMapping];

NSData *data = [string dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *newString = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];