ios - 在 nsdictionary 上排序给出的结果与在 nsarray 上排序不同

Question

2天前，我问了一个问题:如何按字符串对象中的第二个单词对元素进行排序

我得到了解决方案here

但现在我遇到了新问题

考虑我有

nsarray with--> 名称和

nsdictionary，以相同的名称(nsarray)作为值，电子邮件 ID 作为键

我的nsarray包含

   "Test Teacher"

   "Anonymous"

   "Dok Teacher"

我的nsdictionary包含

   "Dok Teacher" --"a@g.com"

   "Anonymous" --  "b@g.com"

   "Test Teacher" --"c@g.com"

由于需要对这些数组和字典进行排序，我使用上面链接中给出的方法对它们进行了排序

但排序后我得到的数据如下

在第二个单词上排序后的 nsarray

   "Anonymous"

   "Test Teacher"

   "Dok Teacher"

排序后的 nsdictionary 对值的第二个单词进行排序

   "Anonymous" --  "b@g.com"

   "Dok Teacher" --"a@g.com"

   "Test Teacher" --"c@g.com"

在使用相同的排序方法后，为什么 Dok Teacher 和 Test Teacher 在字典和 nsarray 中的位置不同。

以及如何以相同的顺序获取数组和字典。

对 nsarray 进行排序的代码:

NSMutableArray *sortedArray = [NSMutableArray arrayWithArray:[teachersNames sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
        NSString *firstTeacher2ndWord = [[[((NSString*)a) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        NSString *secondTeacher2ndWord = [[[((NSString*)b) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        return [firstTeacher2ndWord compare:secondTeacher2ndWord];
    }]];

    NSLog(@"After %@",sortedArray);

    teachersSrc=[NSMutableArray arrayWithArray:sortedArray];

对 nsdictionary 进行排序的代码

    myArray = [teachersList keysSortedByValueUsingComparator:^NSComparisonResult(id a, id b) {
        NSString *firstTeacher2ndWord = [[[((NSString*)a) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        NSString *secondTeacher2ndWord = [[[((NSString*)b) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        return [firstTeacher2ndWord compare:secondTeacher2ndWord];
    }];

    NSLog(@"After %@",myArray);

编辑:

我还尝试过对数组和字典的名字进行排序，然后对两者的姓氏进行排序，但它根本不起作用，

Answer 1

鉴于你有这个:

 NSArray *array = @[@"Test Teacher",@"Anonymous",@"Dok Teacher"];
 NSDictionary *dictionary = @{@"a@g.com":@"Dok Teacher",@"b@g.com":@"Anonymous",@"c@g.com":@"Test Teacher"};


//sort the array first
    NSArray *sortedArray = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    NSString *firstTeacher2ndWord  =[[(NSString *)obj1 componentsSeparatedByString:@" "]lastObject];
     NSString *secondTeacher2ndWord =[[(NSString *)obj2 componentsSeparatedByString:@" "]lastObject];


    if([firstTeacher2ndWord compare:secondTeacher2ndWord options:NSCaseInsensitiveSearch] == FALSE){ // means they are the same
        //compare full text
        firstTeacher2ndWord = (NSString *)obj1;
        secondTeacher2ndWord = (NSString *)obj2;
    }

    return [firstTeacher2ndWord compare:secondTeacher2ndWord options:NSCaseInsensitiveSearch];
}];

 NSLog(@"Sorted Array %@",sortedArray);

//sort the dictionary key using values
    NSArray *sortedDictionaryKey =[dictionary keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2) {
      NSString *firstTeacher2ndWord  =[[(NSString *)obj1 componentsSeparatedByString:@" "]lastObject];
     NSString *secondTeacher2ndWord =[[(NSString *)obj2 componentsSeparatedByString:@" "]lastObject];


    if([firstTeacher2ndWord compare:secondTeacher2ndWord options:NSCaseInsensitiveSearch] == FALSE){ // means they are the same
        //compare full text
        firstTeacher2ndWord = (NSString *)obj1;
        secondTeacher2ndWord = (NSString *)obj2;
    }


    return [firstTeacher2ndWord compare:secondTeacher2ndWord options:NSCaseInsensitiveSearch]
}];

//get the values from the dictionary based on the sorted keys
 NSLog(@"Sorted Dictionary %@",[dictionary objectsForKeys:sortedDictionaryKey notFoundMarker:[NSNull null]]);

会给你这个输出:

//Sorted Array
Sorted Array(
Anonymous,
"Dok Teacher",
"Test Teacher"
)

//Sorted Dictionary
Sorted Dictionary(
    Anonymous,
    "Dok Teacher",
    "Test Teacher"
  )