iphone - 将数组排序到字典中

Question

我有许多字符串的数组。 我不想将它们分类到字典中，因此所有以相同字母开头的字符串都进入一个数组，然后该数组成为键的值；键将是其值数组中所有单词的开头字母。

例子

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

我该怎么做？ 非常感谢!

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);