Incompatible pointer types sending 'NSSortDescriptor *__strong' to parameter of type 'NSArray *

Question

I am sorting my NSSet using :

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
[[testSet.questions allObjects] sortedArrayUsingDescriptors:descriptor]; // warning

But it causes warning :

Incompatible pointer types sending 'NSSortDescriptor *__strong' to parameter of type 'NSArray *

Answer 1

您正在传递期望数组的单个描述符，请尝试以下操作：

[testSet.questions allObjects] sortedArrayUsingDescriptors:@[descriptor]];

Answer 2

You should see this method. It requires you to pass an Array object to it, not a NSSortDescriptor object.

  [sortDescriptions sortedArrayUsingDescriptors:<#(NSArray *)#>]

so you have to create an array and put your NSSortDescriptor object in it. Try this

  NSArray *_sortArray = [[NSArray alloc] initWithObjects:descriptor, nil];
  [testSet.questions allObjects] sortedArrayUsingDescriptors:_sortArray];

  or

  [testSet.questions allObjects] sortedArrayUsingDescriptors:@[descriptor]];

see if it could help:)

Answer 3

NSSortDescriptor should be passed in an array. So you have to create an array then add the descriptor in the array. Now you should pass the array instead of NSSortDescriptor :

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
NSArray *descriptorArray = [NSArray arrayWithObject:descriptor]
[[testSet.questions allObjects] sortedArrayUsingDescriptors:descriptorArray];

Answer 4

Try this :

NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
[[testSet.questions allObjects] sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];

Hope this will help.