Case Insensitive Compare with Core Data and Swift

Swift 3 - 5.0 Syntax

let sortDescriptor = NSSortDescriptor(key: "KeyName", ascending: true, selector: #selector(NSString.caseInsensitiveCompare))

The selector is caseInsensitiveCompare:, with the colon, and you can use it with Core Data.

The colon is there because the method (which is an instance method of NSString) takes one argument (the string to compare with).

As list of sort selectors which can be used with Core Data and a SQLite store can be found in Persistent Store Types and Behaviors in the Core Data Programming Guide.