ios - Swift 3.1 Coredata Sorting Alphabetically Ascending but Keep Records Starting with Numbers in the Beginning -


i have used coredata in 1 of ios projects. have table named "books" (columns: title, author, status, publishdate) , need fetch records in way ordered column title in ascending mode. have written accomplish it:

let fetchrequest = nsfetchrequest<nsfetchrequestresult>.init(entityname: "books")  let sort = nssortdescriptor(key: "title", ascending: true)  fetchrequest.sortdescriptors = [sort]  {     let result = try coreviewcontext.fetch(fetchrequest) } catch let err nserror {     print(err.debugdescription) }

what if have books titles "100 stories, 20 movies, 300 men"? want such titles @ beginning of result array. such records lie in between.

i recommend converting coredata result array of book objects (which assume anyway) implementing custom sorter function. function below: 

static func sortbytitle(books: [book]) -> [book]{     return books.sorted(by: sorterfortitlesalphanumeric) }

the implementation sorterfortitlesalphanumeric this:

//compare book's title book's title static func sorterfortitlesalphanumeric(this : book, that: book) -> bool {     return this.title < that.title }

that give finer grain control trying use pre-baked nssortdescriptor. way if later down road decide filter based on title , publish date can change above function 

    //compare book's title book's title static func sorterfortitlesalphanumeric(this : book, that: book) -> bool {     if this.title == that.title {         return this.publishdate < that.publishdate      }     return this.title < that.title }

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