如何按升序排序NSMutableArray，iPhone？

Question

我有SQLite数据库（DB）并将其作为模型类并在NSMutableArray中获取数据库。 我的DB与此DB类似。 学生名称| RegisterNumber | DatesOfJoin（DoJ）我在tableView中成功显示了DoJ，但我想在tableView中按升序和降序排序DatesOfJoin。 任何帮助将不胜感激，并提前感谢您。

Answer 1

您可以使用NSSortDescriptor和sortUsingDescriptors:sortDescriptors对可变数组进行排序。

NSSortDescriptor *sortDescriptor;
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"DatesOfJoin" ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
[array sortUsingDescriptors:sortDescriptors];
[sortDescriptor release];

Answer 2

请查看官方文档： http ： //developer.apple.com/library/ios/#documentation/cocoa/reference/foundation/Classes/NSArray_Class/NSArray.html

你有很多方法来对数组进行排序：

- (NSArray *)sortedArrayUsingFunction:(NSInteger (*)(id, id, void *))comparator context:(void *)context

- (NSArray *)sortedArrayUsingSelector:(SEL)comparator

- (NSArray *)sortedArrayUsingComparator:(NSComparator)cmptr

- (NSArray *)sortedArrayWithOptions:(NSSortOptions)opts usingComparator:(NSComparator)cmptr

Answer 3

对于降序：

NSArray *sorted = [Arr sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    if ([obj1 intValue] < [obj2 intValue]) return NSOrderedDescending;
    else return NSOrderedAscending;
}];

对于Asending Order：

NSArray *sorted = [Arr sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    if ([obj1 intValue] < [obj2 intValue]) return NSOrderedAscending;
    else return NSOrderedDescending;
}];

Answer 4

您可以尝试使用：

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"Over here your key" ascending:YES]; //Just write the key for which you want to have sorting & whole array would be sorted.
[self.messageAry sortUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];
[descriptor release];

希望有效，

Answer 5

    NSString *res =[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
    //Sorting an array
    NSMutableArray *sortArray = [res valueForKey:@"Year"];
    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:nil ascending:NO selector:@selector(localizedCompare:)];
    yearArray = [sortArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];

在Swift 3.0版本中

let sortedCapitalArray = yourArray.sorted {($0 as AnyObject).localizedCaseInsensitiveCompare(($1 as AnyObject)as! String) == ComparisonResult.orderedAscending}