Question

I have and array of many strings.
I wan’t to sort them into a dictionary, so all strings starting the same letter go into one array and then the array becomes the value for a key; the key would be the letter with which all the words in it’s value’s array begin.

Example

Key = "A" >> Value = "array = apple, animal, alphabet, abc ..."
Key = "B" >> Value = "array = bat, ball, banana ..."

How can I do that?
Thanks a lot in advance!

Answer 1

NSArray *list = [NSArray arrayWithObjects:@"apple, animal, bat, ball", nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
for (NSString *word in list) {
    NSString *firstLetter = [[word substringToIndex:1] uppercaseString];
    NSMutableArray *letterList = [dict objectForKey:firstLetter];
    if (!letterList) {
        letterList = [NSMutableArray array];
        [dict setObject:letterList forKey:firstLetter];
    }
    [letterList addObject:word];
}
NSLog(@"%@", dict);