Sort characters in NSString into alphabetical order

Question

I\'m trying to re-arrange words into alphabetical order. For example, tomato would become amoott, or stack would become ackst.

I\'ve found some methods to do this in

Answer 1

Just another example using NSMutableString and sortUsingComparator:

NSMutableString *mutableString = [[NSMutableString alloc] initWithString:@"tomat"];
[mutableString appendString:@"o"];
NSLog(@"Orignal string: %@", mutableString);

NSMutableArray *charArray = [NSMutableArray array];
for (int i = 0; i < mutableString.length; ++i) {
    [charArray addObject:[NSNumber numberWithChar:[mutableString characterAtIndex:i]]];
}

[charArray sortUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
    if ([obj1 charValue] < [obj2 charValue]) return NSOrderedAscending;
    return NSOrderedDescending;
}];

[mutableString setString:@""];
for (int i = 0; i < charArray.count; ++i) {
    [mutableString appendFormat:@"%c", [charArray[i] charValue]];
}

NSLog(@"Sorted string: %@", mutableString);

Output:

Orignal string: tomato
Sorted string: amoott