cocoa - Help sorting an NSArray across two properties (with NSSortDescriptor?) -


I'm a bit of a NSSortDescriptor n00b, I think, though, what I should do, this is the right tool:

I have NSARR which contains objects with keys, say "name" and "time". Instead of talking about it, here's an example: 

  Input: Name: Time B: 4C: 8B: 5C: 4A: 3C: 2A: 1A : 7B: 6 Desired output: Name: Time A: 1 & lt; --- A: 3A: 7C: 2 & lt; --- C: 4C: 8b: 4 & lt; --- B: 5b: 6

So the values ​​are sorted by "time" and are grouped by "name" first comes first because its shortest time value , And all prices for A come after each other. Then comes, he had the second smallest value of all his values. I have indicated the values ​​that determine how the names have been resolved; Each name occurs within the group, sorting time.

How do I get the most efficient way to get NSA output from input? (CPU- and memory-wise, code is not required.) How do I build nssort descriptors for this, or use any other method? Unless this is the most effective way, I do not want to do my own role.

NSArray The method you need is most important:

The first descriptor specifies the primary key path for sorting the receiver's contents, any subsequent explanation is used to sort objects with duplicate values. See NSSortDescriptor for additional information. Some filtering is also required with

NSPredicate : 

  NSSortDescriptor * timeSD = [NSSortDescriptor sortDescriptorWithKey: @ "time" ascending : Yes]; NSMutableArray * Sorted Time = [Unassigned Array Sorting Using Desktops: TimeSide]; NSMutableArray * SortedArray = [NSMutableArray arrayWithCapacity: [sortedByTime count]]; While ([Sorted time calculation]) {id groupLead = [sorted byte time objectindex: 0]; NSPredicate * groupPredicate = [NSPredicate predicateWithFormat: @ "name =% @", [group title]] ;; NSArray * Group = [Sorted Time FilterAruusingProx: Group Advanced]; [Sortedray add objectframe: group]; [Extracted bytime timeBizjectInternet: group]; }

I do not know that this is the most effective way, but unless you have a reason to believe that it is causing problems, to worry about performance related effects There is no need for that. It is premature adaptation. I will not have any worries about the performance of this method. You have to rely on the framework otherwise you will have to rewrite it (thus weakening the point of the structure) because the reason for a unflinching paranoia


Comments

Post a Comment

Popular posts from this blog

sql - dynamically varied number of conditions in the 'where' statement using LINQ -

I am using my first project LINQ (in mvc), so maybe there's something very simple that I remember. However, a day of searching and experimenting does not work, so it works. I am trying to write a LINQ query (Linux to SQL) in which in many cases where the statement is different from an OR or an AND. We do not know how many conditions are going in the query till runtime. This search is for filter control, where the user can choose multiple criteria for filtering. Select from table where table.col = 1 or table.col = 2 or table.col = 7 .... 'Other number of conditions Before I just create the SQL query as a string, while looping over all the situations. However, it seems that there should be a good way to do this in LINQ. I tried to use Expression trees, but they had a second thought for this moment on my head, where the lambda function was to be executed inside the statement such as: values ​​for matchingRows = matchingRows for each value Where (function (row) row.c...
Read more

asp.net mvc - Dynamically Generated Ajax.BeginForm -

I have a problem with ASP.NET MVC Ajax forms. I generate many Ajax form in a table such as: & Lt; Input type = "submit" name = "activity" value = "add activity" / & gt; & Lt;%}% & gt; & Lt; / TD & gt; & Lt; / TR & gt; & Lt;%}% & gt; So far so good. When I post one of those forms, it gives a partial view in a div, and in this new partial view a new Ajax Beginnform (which is not in Genesis form) This second Ajax Beginnorf is exactly like the ones I got on the table, but when I post it, I do not get the "Ajax Post", but a normal post that sends me to a new page, I do not know whether the two Ajax forms What is the reason for the difference between, why is it the "dynamically generated" Ajax form behaves like a normal HTML form? By the way, I know that I can do it in different ways using javascript, but I would like to understand whether it can only be done using MVC helplars and Ajax lib...
Read more

Debug on symbian -

I am using trk for phone debug This works well for the Holorld project But when I start the project in phone debug mode 1) the load failed 2) TrkProtocolPlugin: to target the specified file Failure (please verify If any body understands what problem I am experiencing, then this problem helps me Pre-release If the application has the privileges assigned (with the appropriate certificate) itemprop = "text" > In your case, I will check: / li> If there is no conflict of application ID with any other application of device If there are problematic commands in the installation package (for example copy copy for non-accessible directories)
Read more